CCNA V2.0 Questions and Flash Cards
Solicited Node Multicast Address
FF02:0:0:0:0:1:FF/104; last 24-bits taken from interface-ID; automatically provisioned like link-local addresses; used for L3-to-L2 address resolution
C • Wireless networks broadcast data over a medium that allows easy access.
Why is security so important in wireless networks? A • Wireless networks are typically slower than wired networks. B • Televisions and other devices can interfere with wireless signals. C • Wireless networks broadcast data over a medium that allows easy access. D • Environmental factors such as thunderstorms can affect wireless networks.
D. to enable the switch to be managed remotely
Why would a Layer 2 switch need an IP address? A. to enable the switch to receive frames from attached PCs B. to enable the switch to send broadcast frames to attached PCs C. to enable the switch to function as a default gateway D. to enable the switch to be managed remotely
to copy an existing configuration into RAM
Why would a technician enter the command copy startup-config running-config?
The default gateway address is used to forward packets originating from the switch to remote networks. Refer to curriculum topic: 6.4.3 A default gateway address allows a switch to forward packets that originate on the switch to remote networks. A default gateway address on a switch does not provide Layer 3 routing for PCs that are connected on that switch. A switch can still be accessible from Telnet as long as the source of the Telnet connection is on the local network.
Within a production network, what is the purpose of configuring a switch with a default gateway address?
UDP will not disrupt the game to retransmit dropped packets.
You are creating a network-based video game. What influences your decision about which transport protocol to use for the application?
FDDI
__________ has both physical and logical ring topologies.
802.3
___________is a working group and a collection of IEEE standards produced by the working group defining the physical layer and data link layer's media access control (MAC) of wired Ethernet.
T3
aka DS3, 28 DS1s (T1s) bundled together, 44.736 Mbps
DUAL (defusing update algorithm)
algorithm EIGRP uses to learn, track, determine best route; successor (best route having lowest total metric, distance); Feasible successor (backup routes with higher metrics); feasible distance (best, lowest, total distance between local router and destination prefix); Reported distance (distance from neighbor to destination); Neighbor table (neighbor info is recorded); EIGRP topology table (backup routes recorded; routing table (best routes recorded)
Variance
allows unequal cost load-balancing: router(config)# router eigrp 100; router(config-rtr)# variance X; X is simply a multiplier (mulitiply FD of all routes in topology table by "X" = result "YY" for each route; compare result "YY" against all Feasible Successors; if distance of any FS routes <= YY, install route in table)
T1
also called DS1, 24-DS0s 1.544 Mbps
Committed Information Rate (CIR)
amount of data rate that a service provider guarantees; anything above the [TERM] is considered as burst
Standard ACL
filters traffic based on layer 3 header; source IP address is checked; ACL standard numbers range from 1-99; should be applied nearest to destination; no intelligence of checking destination address and port numbers Applying configuration: router(config-if)# ip access-group <ACL no> <in | out> Configuration: router(config)# access-list <ACL no> <permit | deny> <source address> <wild card mask> Verification: router# show ip access-list; router# show ip interface; router# show run | inc access-list
Configures the PVC address on a serial interface or subinterface
frame-relay interface-dlci
Configures the LMI type on a serial link
frame-relay lmi-type
Creates a static mapping for use with a Frame Relay network
frame-relay map protocol address
Creates a multipoint subinterface on a serial link that can be used with Frame Relay networks
interface s0.16 multipoint
Creates a point-to-point subinterface on a serial link thatcan be used with Frame Relay
interface s0.16 point-to-point
Sets the type of ISDN switch that the router will communicate with. Can be set at interface level or global configuration mode
isdn switch-type
Puts you in configuration mode to change or set your user mode passwords
line
Changes a 2501 to boot without using the contents of NVRAM
o/r 0x2142
Port Address Translation (PAT)
one to many mapping; one public address can provide multiple host connections; usually deployed at client end; easier from the perspective of scalability Configuration - Router(config-if)# ip nat inside; Router(config-if)# ip nat outside; Router(config# access-list < acl no> <permit | deny > <source-address> <wildcard mask>; Router(config)# ip nat pool <name> <start-address> <end-address> netmask< subnet mask>; Router( config)# ip nat inside source list < acl no> pool <name> overload Verification: Router# show ip nat translation
Access Control List (ACL)
packet filtering mechanism; can filter packets on the basis of layer 3 and layer 4 header; should have at least one permit statement; works in sequential order, statement with lower sequence is preferred and checked; only one ACL can be applied per interface, per direction; each line in ACL is ACE, access control entry; Can be applied inbound and outbound (Inbound before routing, Outbound after routing); Implicit deny rule applied at the end of the sequence if nothing has been defined; Types of ACLs - standard ACL; extended ACL; named ACL (standard named, extended named) Configuration: router(config)# access-list <ACL no> <permit|deny> <protocol> <source address> <wildcard mask> <dest address> <wildcard mask> <port numbers> Verification: router# show ip access-list; router# show ip interface; router# show run | inc access-list Apply configuration: router(config-if)# ip access-group <ACL no> <in|out>
Shows the directly connected neighbors and the details about them
show cdp neighbor
Shows the IP address and IOS version and type, and includes all of the information from the show cdp neighbor command
show cdp neighbor detail
Shows the IPX access lists configured on a router
show ipx access-list
Shows the RIP and SAP information being sent and received on an individual interface. Also shows the IPX address of the interface
show ipx interface
Shows the IPX routing table
show ipx route
Shows the SAP table on a Cisco router
show ipx servers
Shows the RIP and SAP information sent and received on a Cisco router
show ipx traffic
Shows the number called and whether a call is in progress
show isdn active
Shows if your SPIDs are valid and if you are connected and communicating with the provider's switch.
show isdn status
Shows the routed protocols and network addresses configured on each interface
show protocols
Displays the running-config file; Short for show running-config
show run
C. displaying a list of all available commands within the current mode D. determining which option, keyword, or argument is available for the entered commandWhich two functions are provided to users by the context-sensitive help feature of the Cisco IOS CLI?
(Choose two.) A. providing an error message when a wrong command is submitted B. selecting the best command to accomplish a task C. displaying a list of all available commands within the current mode D. determining which option, keyword, or argument is available for the entered command E. allowing the user to complete the remainder of an abbreviated command with the TAB key
R1: G0/0 and S0/0/0 R2: G0/1 and S0/0/0 R1>enable R1# show ip int brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 192.168.20.1 YES manual up up GigabitEthernet0/1 192.168.30.1 YES manual administratively down down Serial0/0/0 209.165.200.225 YES manual up up Serial0/0/1 unassigned YES unset administratively down down Vlan1 unassigned YES unset administratively down down R2>enable R2#show ip int brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 10.1.2.1 YES manual administratively down down GigabitEthernet0/1 10.1.3.1 YES manual up up Serial0/0/0 209.165.200.226 YES manual up up Serial0/0/1 unassigned YES unset administratively down down Vlan1 unassigned YES unset administratively down down Refer to curriculum topic: 6.4.2 The command to use for this activity is show ip interface brief in each router. The active and operational interfaces are represented by the value "up" in the "Status" and "Protocol" columns. The interfaces in R1 with these characteristics are G0/0 and S0/0/0. In R2 they are G0/1 and S0/0/0.
Here is a link to the PT ActivityView in a new window. Open the PT activity. Perform the tasks in the activity instructions and then answer the question. Which interfaces in each router are active and operational?
A • ARP
Host A needs to learn the MAC address of Host B, which is on the same LAN segment. A message has been sent to all the hosts on the segment asking for the MAC address of Host B. Host B responds with its MAC address and all other hosts disregard the request. What protocol was used in this scenario? A • ARP B • DHCP C • DNS E • WINS
They have to keep their own local routing table that contains a route to the loopback interface, a local network route, and a remote default route.
How do hosts ensure that their packets are directed to the correct network destination?
As an "uptime" annual percentage that is calculated by taking the number of minutes the network is available and dividing it by the number of minutes in a year, which is 525,600.
How is network Availability measured?
As the Mean time between Failures - or MTBF - which is a measurement used to indicate the likelihood of a component failing.
How is network Reliability measured?
Native VLAN
IEEE 802.1Q supported feature; Frame without tag is considered native VLAN traffic; Must match on both ends of the trunk; By default, native VLAN is 1; Can be changed using the switchporttrunk native vlan<vlan-id>command
Spanning-Tree Protocol (STP)
IEEE 802.1d; Legacy protocol to prevent Layer 2 loop; Usually called CST (Common Spanning Tree); No redundancy in traffic paths for frames; Timers: Hello (2 seconds), Max Age (20 seconds), Forward Delay (30 seconds); STP Calculation: Elects root bridgebased on the lowest BID, where BID consists of priority and MAC; Elects designated port, root port, and blocking ports based on STP cost or port priority; Provides loop-free path and seamless convergence during failure; Remember that with STP...LOWER is BETTER
Extended IP Access List
IP access list that filters the network by logical address, protocol field in the Network layer header, and even the port field in the Transport layer header
Standard IP Access List
IP access list that uses only the source IP addresses to filter a network
Is a global configuration command used to tell a router to forward packets to a default route when the destination network is not in the routing table
IP classless
B • default route
If a router receives a packet that it does not know how to forward, what type of route must be configured on the router to prevent the router from dropping it? A • dynamic route B • default route C • destination route D • default destination
The host can communicate with other hosts on the local network, but is unable to communicate with hosts on remote networks.
If the default gateway is configured incorrectly on the host, what is the impact on communications?
B • The host can communicate with other hosts on the local network, but is unable to communicate with hosts on remote networks.
If the default gateway is configured incorrectly on the host, what is the impact on communications? A • The host is unable to communicate on the local network. B • The host can communicate with other hosts on the local network, but is unable to communicate with hosts on remote networks. C • The host can communicate with other hosts on remote networks, but is unable to communicate with hosts on the local network. D • There is no impact on communications.
Password Authentication Protocol (PAP)
In PPP networks, a method of validating connection requests. The requesting (remote) device must send an authentication request, containing a password and ID, to the local router when attempting to connect. Unlike the more secure CHAP (Challenge Handshake Authentication Protocol), this sends the password unencrypted and does not attempt to verify whether the user is authorized to access the requested resource; it merely identifies the remote end
It requires that packets coming into the router be responses to internal host requests.
In the Linksys Security menu, what does the SPI Firewall Protection option Enabled provide?
Routing Updates
Incremental update (Only changes are sent in the routing update); Full update (All of the routing table is sent in the update); Periodic update (Sent in the specified time interval); Triggered update (Sent whenever change is detected)
Named ACL
Individual statements can be edited, unlike numbered ACLs; can be used with naming convention; use of name instead of number makes management easier; more flexible than numbered ACLs
Layered Architecture
Industry standard way of creating applications to work on a network; allows the application developer to make changes in only one layer instead of the whole program
Puts you in interface configuration mode for a FastEthernet port. Also used with show commands
Interface fastethernet 0/0
Creates a subinterface Interface serial 5 Puts you in configuration mode for interface serial 5 and can be used for show commands
Interface fastethernet 0/0.1
Asynchronous Transfer Mode (ATM)
International standard, identified by fixed-length 53-byte cells, for transmitting cells in multiple service systems, such as voice, video, or data. Transit delays are reduced because the fixed-length cells permit processing to occur in the hardware; designed to maximize the benefits of high-speed transmission media, such as SONET, E3, and T3; fiber used in [TERM] core network; last mile could be copper or fiber, mostly fiber; cells always same, fixed size of 53 bytes; primarily designed for latency sensitive apps
Wide Area Network (WAN)
Is a designation used to connect LANs together across a DCE (data communications equipment) network. Typically, it is a leased line or dial-up connection across a PSTN network. Examples of these protocols include Frame Relay, PPP, ISDN, and HDLC
0.0.0.0 255.255.255.255
Is a wildcard command; same as the any command
Network Termination 2 (NT2)
Is an ISDN designation to devices that do not understand ISDN standards. To use this, you must use a terminal adapter (TA)
Network Termination 1 (NT1)
Is an ISDN designation to devices that understand ISDN standards
Organizationally Unique Identifier (OUI)
Is assigned by the IEEE to an organization that makes network interface cards. The organization then puts it on each and every card they manufacture; 3 bytes (24 bits) long. The manufacturer then adds a 3-byte identifier to uniquely identify the host on an internetwork. The total length of the address is 48 bits (6 bytes) and is called a hardware address or MAC address
Registered Jack (RJ) Connector
Is used with twisted-pair wiring to connect the copper wire to network interface cards, switches, and hubs
Data Link Layer
Layer 2 of the OSI reference model, it ensures the trustworthy transmission of data across a physical link and is primarily concerned with physical addressing, line discipline, network topology, error notification, ordered delivery of frames, and flow control. The IEEE has further segmented this layer into the MAC sublayer and the LLC sublayer. Also known as the Link layer. Can be compared somewhat to the Data Link control layer of the SNA model; MAC (48-bit addressing system; Example: aaaa.aaaa.aaaa; First 24 bits are considered OUI; Remaining 24 bits are considered vendor assigned); LLC (WAN protocols; PPP; HDLC; Frame Relay); Example: Switch, bridge; PDU: FRAMES
Transport Layer
Layer 4 of the OSI reference model, used for reliable communication between end nodes over the network; provides mechanisms used for establishing, maintaining, and terminating virtual circuits, transport fault detection and recovery, and controlling the flow of information
Session Layer
Layer 5 of the OSI reference model, responsible for creating, managing, and terminating sessions between applications and overseeing data exchange between Presentation layer entities
Presentation Layer
Layer 6 of the OSI reference model, it defines how data is formatted, presented, encoded, and converted for use by software at the Application layer; only layer of the OSI that can actually change data
Application Layer
Layer 7 of the OSI reference network model, supplying services to application procedures (such as electronic mail or file transfer) that are outside the OSI model. This layer chooses and determines the availability of communicating partners along with the resources necessary to make the connection, coordinates partnering applications, and forms a consensus on procedures for controlling data integrity and error recovery.
Session
Layer responsible for dialog Control
Transport
Layer responsible for end-to-end connection. Also segments and reassembles data into a single data stream. TCP and UDP live here.
Data link
Layer responsible for framing
Network
Layer responsible for routing
F • Disable the wireless network when a vulnerability analysis is being performed.
Many best practices exist for wired and wireless network security. The list below has one item that is not a best practice. Identify the recommendation that is not a best practice for wired and wireless security. A • Periodically update anti-virus software. B • Be aware of normal network traffic patterns. C • Periodically update the host operating system. D • Activate the firewall on a Linksys integrated router. E • Configure login permissions on the integrated router. F • Disable the wireless network when a vulnerability analysis is being performed.
Dynamic NAT
Many to many mapping; one private host requires a public IP address obtained from a pool of available addresses; usually deployed at client end; easier from the perspective of scalability Configuration: router(config-if)# ip nat inside; router(config-if)# ip nat outside; router(config)# access-list <acl no> <permit|deny> <source-address> <wildcard mask>; router(config)#ip nat pool <name> <start-ip> <end-ip> netmask <subnet mask>; router(config)# ip nat inside source list <acl no> pool <name> Verification: Router# show ip nat translation
provides security on the console = router(config-line)# Password class displays a message when the router is accessed = router(config)# banner motd configures a name on the router = router(config)# hostname CL1
Match the commands to the correct actions. (Not all options are used.)
Setup Mode
Mode that a router will enter if no configuration is found in nonvolatile RAM when the router boots. Allows the administrator to configure a router step-by-step. Not as robust or flexible as the Command-Line Interface
Copper and fiber cabling. Ethernet, Fast Ethernet (FE), Gigabit Ethernet (GE), Token Ring, and fiber distributed data interface (FDDI).
Name 6 types of media used in a LAN.
"Hubs, bridges, switches, routers, firewalls, wireless access points, modems, NT1s (Network Terminator Type 1 is an ISDN network termination device), and channel service units/data service units (CSU/DSUs)."
Name 9 common network components.
PCs, file servers, hubs, bridges, switches, routers, multilayer switches, voice gateways, and firewalls.
Name 9 network devices commonly found in a LAN.
Analog dialup, asynchronous transfer mode (ATM), dedicated circuits, cable, digital subscriber line (DSL), Frame Relay, Integrated Services Digital Network (ISDN), Switched Multi-megabit Data Services (SMDS), and X.25
Name 9 services available via a WAN.
1) Small Office/Home Office (SOHO) - Home or small office with a handful of people. 2) Branch Office - Users are connected in a small area that is geographically separated from the corporate office. 3) Mobile Users - Can connect to the network from any location, LAN, or Wan. 4) Corporate or Central Office - Most of the network users and resources are located in one location.
Name and describe the 4 types of networking locations.
Flat Network
Network that is one large collision domain and one large broadcast domain
Network Layer
OSI Layer 3—the layer in which routing is implemented, enabling connections and path selection between two end systems
Network Layer
OSI Layer 3—the layer in which routing is implemented, enabling connections and path selection between two end systems; Routed protocol (Protocols that are used for identification; IP, IPX, AppleTalk); Routing protocol (Protocols that are used to find the routed protocols; EIGRP, OSPF, etc.); PDU: PACKETS
Transport Layer
OSI Layer 4; used for reliable communication between end nodes over the network; provides mechanisms used for establishing, maintaining, and terminating virtual circuits, transport fault detection and recovery, and controlling the flow of information Identifying services; TCP (Connection oriented; Reliable; Protocol number 6); UDP (Connectionless; Unreliable; Protocol number 17); Multiplexing and de-multiplexing; Fragmentation; Sequencing and reassembling; Windowing, buffering, congestion avoidance; Error correction; PDU: SEGMENTS
Presentation Layer
OSI Layer 6; defines how data is formatted, presented, encoded, and converted for use by software at the Application layer; Performs encryption within an application; Ensures that data is presented correctly to the application used; Performs translation of cross-platform standards that may be understood by the local machine: (Pict. into .jpg file translation; .wav into .mp3)
OSPF DR & BDR election
OSPF elects a DR (designated router) and a BDR (backup designated router) in broadcast and non-broadcast multi-access networks; DR is responsible for sending an update to the neighbors that are received from other neighbors; Special multicast address used for sending routing updates to DR/BDR: 224.0.0.6 | OSPF router with the highest priority becomes the DR; OSPF router with lower priority than DR becomes BDR; a BDR takes DR's if DR fails; other OSPF routers are known as DROTHERS; If OSPF priority hasn't been configured, highest router-id is referenced; OSPF router with highest router-id becomes DR; OSPF router with lower router-id than DR's becomes the BDR
Well-known Ports
(Ranges from 0 to 1023; Port numbers used by well-known services; Examples: HTTP(80), HTTPS(443), DNS(53), FTP(20,21), TELNET(23), etc.)
Wildcard Masks
0's mean match this, 1's ignore; if only want odd numbers, wildcard mask of 11111110 (4x) or 254.254.254.254
Switch
1) In networking, a device responsible for multiple functions such as filtering, flooding, and sending frames. It works using the destination address of individual frames; operate at the Data Link layer of the OSI model. 2) Broadly, any electronic/mechanical device allowing connections to be established as needed and terminated if no longer necessary; considered hardware based, bridges are software based
IPv6
128-bit addressing system; expressed in hexadecimal instead of decimal; colon ":" used to separate group of four-hex characters (a "word"); 4 bits = 1 hex character; IPv6 addresses are complex and not easy to write like IPv4; can be suppressed to minimize overhead (leading zeros in each word can be omitted; single set of consecutive zeroes can be replaced with double colon "::"; multiple double colons not allowed Configuration: router(config-if)# ipv6 address <address> / <prefix-length> <EUI-64>; router(config-if)# ipv6 address autoconfig <default>; router(config-if)# no shutdown IPv6 header - version; traffic class; flow label; payload length; next header; hop limit; source address; destination address IPv6 Static Routes - purpose is same ase IPv4 static routes; must supply destination prefix, mask and next-hop; router(config)# ipv6 route <destination-prefix/mask> <next-hop>; ex: Router(config)#ipv6 route 2001:2:3:4::/64 2001:aa:bb:cc::77 IPv6 Verification: router# show ipv6 interface brief; router# show ipv6 routers; router# show ipv6 route; router# debut ipv6 nd IPv6, Enabling: Router(config)# ipv6 unicast-routing - permits router to send ICMPv6 router advertisements; allows IPv6 routing between connected interfaces; allows operation of IPv6 routing protocols
Rapid STP (RSTP)
802.11w; Enhancement to legacy 802.1d STP; Designed to speed up convergence; Link type is derived from duplex mode; Full duplex link is considered as a P2P; Half duplex link is assumed to be shared
Configuration Register
A 16-bit configurable value stored in hardware or software that determines how Cisco routers function during initialization. In hardware, the bit position is set using a jumper. In software, it is set by specifying specific bit patterns used to set startup options, configured using a hexadecimal value with configuration commands
Subnet Mask
A 32-bit address mask used in IP to identify the bits of an IP address that are used for the subnet address. Using a mask, the router does not need to examine all 32 bits, only those selected by the mask
Inter Switch Link (ISL) Routing
A Cisco proprietary method of frame tagging in a switched internetwork. Frame tagging is a way to identify the VLAN membership of a frame as it traverses a switched internetwork
Media Access Control (MAC) Address
A Data-Link layer hardware address that every port or device needs in order to connect to a LAN segment. These addresses are used by various devices in the network for accurate location of logical addresses; defined by the IEEE standard and their length is six characters, typically using the burned-in address (BIA) of the local LAN interface. Variously called hardware address, physical address, burned-in address
Router
A Network-layer mechanism, either software or hardware, using one or more metrics to decide on the best path to use for transmission of network traffic. Sending packets between networks is based on the information provided on Network layers. Historically, this device has sometimes been called a gateway
A crossover cable is being used.
A PC is plugged into a switch and is unable to connect to the network. The UTP cable is suspected. What could be the problem?
Forward Explicit Congestion Notification (FECN)
A bit set by a Frame Relay network that informs the DTE receptor that congestion was encountered along the path from source to destination. A device receiving frames with this bit set can ask higher-priority protocols to take flow-control action as needed
Virtual Circuit
A logical circuit devised to assure reliable communication between two devices on a network. Defined by a virtual path connection (VPC)/virtual path identifier (VPI) pair, a [TERM] can be permanent (PVC) or switched (SVC). VCs are used in Frame Relay and X.25. Known as virtual channel in ATM
Frame
A logical unit of information sent by the Data Link layer over a transmission medium. The term often refers to the header and trailer, employed for synchronization and error control, that surround the data contained in the unit
Hop Count
A routing metric that calculates the distance between a source and a destination. RIP employs [TERM] as its sole metric
Access List
A set of test conditions kept by routers that determines "interesting traffic" to and from the router for various services on the network
Buffer
A storage area dedicated to handling data while in transit; used to receive/store sporadic deliveries of data bursts, usually received from faster devices, compensating for the variations in processing speed. Incoming information is stored until everything is received prior to sending data on.
C • It floods the frame out of all active ports, except the origination port.
A switch receives a frame with a destination MAC address that is currently not in the MAC table. What action does the switch perform? A • It drops the frame. B • It sends out an ARP request looking for the MAC address. C • It floods the frame out of all active ports, except the origination port. D • It returns the frame to the sender.
SVI
A technician configures a switch with these commands: SwitchA(config)# interface vlan 1 SwitchA(config-if)# ip address 192.168.1.1 255.255.255.0 SwitchA(config-if)# no shutdown What is the technician configuring?
ARP cache routing table
A technician is configuring a router that is actively running on the network. Suddenly, power to the router is lost. If the technician has not saved the configuration, which two types of information will be lost? (Choose two.)
Store-and-Forward Packet Switching
A technique in which the switch first copies each packet into its buffer and performs a cyclical redundancy check (CRC). If the packet is error-free, the switch then looks up the destination address in its filter table, determines the appropriate exit port, and sends the packet
Carrier Sense Multiple Access with Collision Detect (CSMA/CD)
A technology defined by the Ethernet IEEE 802.3 committee. Each device senses the cable for a digital signal before transmitting. Also allows all devices on the network to share the same cable, but one at a time. If two devices transmit at the same time, a frame collision will occur and a jamming pattern will be sent; the devices will stop transmitting, wait a predetermined amount of time, and then try to transmit again.
TCP
A user is viewing an HTML document located on a web server. What protocol segments the messages and manages the segments in the individual conversation between the web server and the web client?
the MAC address of the default gateway
A user sends an HTTP request to a web server on a remote network. During encapsulation for this request, what information is added to the address field of a frame to indicate the destination?
Portfast
Access Ports typically connect to hosts (Laptops/PCs, Servers); End users don't want to wait up to a minute to gain network connectivity; designed to speed up this process; When enabled on a port, it places port immediately into Forwarding state upon initial connection; Not to be used on VLAN Trunk ports unless there is certainty about lack-of-loops Configuration - (config-if)#spanning-tree portfast OR (config)#spanning-tree portfast default Verification - Switch#show spanning-tree interface <type/number> portfast
copy running-config startup-config
After troubleshooting a router, the network administrator wants to save the router configuration so that it will be used automatically the next time that the router reboots. What command should be issued?
Network Address Translation (NAT)
An algorithm instrumental in minimizing the requirement for globally unique IP addresses, permitting an organization whose addresses are not all globally unique to connect to the Internet, regardless, by translating those addresses into globally routable address space; Separates LAN from WAN and provides accessibility to the outside world; Translates RFC1918 space addresses into public addresses; Provides security; Helps reduce public IP address consumption; Hides private addresses from outsiders
Local Management Interface (LMI)
An enhancement to the original Frame Relay specification. Among the features it provides are a keepalive mechanism, a multicast mechanism, global addressing, and a status mechanism
B • switch E • wireless access point
An integrated router can normally perform the functions of which two other network devices? (Choose two.) A • NIC B • switch C • e-mail server D • application server E • wireless access point
Interior Gateway Protocol (IGP)
Any protocol used by the Internet to exchange routing data within an independent system Typically works within the Autonomous System; Can be categorized into three sections: Distance vector (Elects shortest path based on the total metric of a route; Visibility of network topology limited; Ex: IGRP, RIPv1/v2); Link state (Elects shortest path based on the link cost; Complete visibility to network topology; Ex: OSPF, IS-IS); Hybrid (Combines features of distance vector and link state; Ex: EIGRP)
access-class
Applies a standard IP access list to a VTY line
Decapsulation
As each layer receives a PDU from the layer below it, headers are inspected and then removed.
Public Addresses
At least one public address is required for a private host to communicate to the Internet; globally routable; Globally unique; Should be purchased; Usually used in Internet edge; Range of public addresses: Beyond the RFC 1918 space, all addresses are public
Network layer
At which layer of the OSI model would a logical address be encapsulated?
Octet
Base-8 numbering system used to identify a section of a dotted decimal IP address. Also referred to as a byte
cdp timer
Changes the CDP update timer
Per-VLAN Spanning Tree (PVST)
Cisco Default; Number of STP instances depends on number of VLANs; Effective where load sharing is required; BPDU is sent for each VLAN; Rapid convergence; Both the encapsulations ISL and IEEE 802.1Q are supported; Consumes resources because of control traffic overhead Verification - Switch# show spanning-tree; Switch# show spanning-tree vlan<vlan-id>; Switch# show spanning-tree root; Switch# show spanning-tree blocked ports Configuring port cost and port priority per VLAN - Switch(config-if)# spanning-tree vlan<vlan-id> port-priority <priority>; Switch(config-if)# spanning-tree vlan<vlan-id> cost <cost> Configuring priority per VLAN - Switch(config)# spanning-tree vlan<vlan-id> priority <priority>; Switch(config)# spanning-tree vlan<vlan-id> root primary; Switch(config)# spanning-tree vlan<vlan-id> root secondary
Cisco Discovery Protocol (CDP)
Cisco's proprietary protocol that is used to tell a neighbor Cisco device about the type of hardware, software version, and active interfaces that the Cisco device is using. It uses a SNAP frame between devices and is not routable; Layer 2 protocol for neighbor discovery; Provides information of platform, interface, IP; address, and OS version; Equivalent to the open standard LLDP; Helps with preparing network diagram Enabling CDP: Router(config)# cdprun, Router(config)# cdptimer <seconds> Disabling CDP: Router(config)# no cdprun, Router(config-if)#no cdpenable Verifying CDP: Router# show cdpneighbor, Router# show cdpneighbor < interface>, Router# show cdpneighbor <interface> detail
clear counters
Clears the statistics from an interface
A • encrypt; authenticate users on
Complete the following sentence: WEP is used to ______ , and EAP is used to _____ wireless networks. A • encrypt; authenticate users on B • filter traffic; select the operating frequency for C • identify the wireless network; compress data on D • create the smallest wireless network; limit the number of users on
Moves forward one character
Ctrl+F
Redisplays a line
Ctrl+R
Returns you to the originating router when you telnet to numerous routers
Ctrl+Shift+6, then X (keyboard combination)
Erases a line
Ctrl+U
Erases a word
Ctrl+W
Ends configuration mode and returns to EXEC
Ctrl+Z
Administrative Distance (AD)
Defines trustworthiness of a routing protocol; 8-bit numbering system; Ranges from 0 through 255
State Transitions
Digital signaling scheme that reads the "state" of the digital signal in the middle of the bit cell. If it is five volts, the cell is read as a one. If the state of the digital signal is zero volts, the bit cell is read as a zero
B • by phone
During a pretexting event, how is a target typically contacted? A • by e-mail B • by phone C • in person D • through another person
Subnetting (in IPv4)
Each IP network that is purchased is only good for a single broadcast domain (VLAN); Often unused/unallocated host space within a given network; Subnetting = Dividing a single, allocated network into multiple sub-networks; Minor loss of available hosts addresses; Every device running IPv4 uses the same process to determine its local network: (Identify local IP address in binary, Identify local subnet mask in binary, Extract network portion of address by comparing current address and subnet mask); Subnet mask is referenced instead of classfull network address; (2^h)-2 = hosts per subnet
Physical Layer
Electrical signals carried over the physical layer; Devices used at the physical layer (Hubs; Repeaters; Network interface cards (NICs); Cables (Ethernet, fiber-optic, serial, etc.)) PDU: BITS
Flash
Electronically Erasable Programmable Read-Only Memory (EEPROM) is this type of memory; Used to hold the Cisco IOS in a router by default
Framing
Encapsulation at the Data Link layer of the OSI model is called [TERM] because the packet is encapsulated with both a header and a trailer
Deletes the startup-config
Erase startup
Moves back one word
Esc+B
Moves forward one word
Esc+F
10Base2 and 10Base5
Ethernet __________ has/have both a physical and logical bus topology.
E1
European, 30-DS0s at 2.048 Mbps
Sets the timeout in seconds and minutes for the console connection
Exec-timeout
ROM
Fill in the blank. In a router,________ is the nonvolatile memory where the diagnostic software, the bootup instructions, and a limited IOS are stored.
Extended ACL
Filters traffic based on layer 3 and layer 4 header; source and destination IP and port numbers are checked; ACL numbers range from 100-199; should be applied nearest to source; capable of transport header inspection
Windowing
Flow-control method used with TCP at the Transport layer of the OSI model
First Hop Redundancy Protocols (FHRP)
Generic term for any protocol that provides redundancy for client default gateway; cisco proprietary (HSRP; HSRPv2; GLBP, gateway load balancing protocol); standardized IETF, VRRP common characteristics - require two or more routers; hello's/keepalives exchanged between routers; one router elected as the active router for clients; sub-second failover; routers share a "virtual IP" and "Virtual MAC"
ATM and SMDS.
Give 2 examples of cell-switched services.
Analog dial-up and ISDN.
Give 2 examples of circuit-switched services.
Frame Relay and X.25.
Give 2 examples of packet-switched services.
Fiber distributed data interface (FDDI).
Give an example of a media technology that uses dual rings to connect computer components.
Diagnostics can be run without a technician being present at the site.
How does remote-access software help in the troubleshooting process?
The MTU is passed to the network layer by the data link layer Refer to curriculum topic: 6.1.2 The data link layer indicates to the network layer the MTU for the medium that is being used. The network layer uses that information to determine how large the packet can be when it is forwarded. When packets are received on one medium and forwarded on a medium with a smaller MTU, the network layer device can fragment the packet to accommodate the smaller size.
How does the network layer use the MTU value?
Extended IPX Access List
IPX access list that filters the network by logical IPX address, protocol field in the Network layer header, or even socket number in the Transport layer header
Standard IPX Access List
IPX access list that uses only the source and destination IPX address to filter a network
S Reference Point
ISDN reference point that works with a T reference point to convert a 4-wire ISDN network to the 2-wire ISDN network needed to communicate with the ISDN switches at the network provider
Connection ID
Identifications given to each Telnet session into a router. The show sessions command will give you the connections a local router will have to a remote router. The show users command will show the connection IDs of users telnetted into your local router
B • vishing C • phishing E • pretexting
Identify three techniques used in social engineering. (Choose three.) A • fishing B • vishing C • phishing D • spamming E • pretexting F • junk mailing
An application that allows you to access and use resources that are not located on your local computer.
In a network, what is a "network-aware" application?
Customer Premises Equipment (CPE)
Items such as telephones, modems, and terminals installed at customer locations and connected to the telephone company network
FragmentFree
LAN switch type that reads into the data section of a frame to make sure fragmentation did not occur; looks at the first 64 bytes of a frame to make sure a collision has not occurred. It is sometimes referred to as modified cutthrough; default for 1900 switches
Router LSA
LSA Type-1; describes the state of connected links; bits to indicate special capabilities of router (ABR, ASBR); confined to local area only
Network LSA
LSA Type-2; only created by designated routers; describes (all adjacent neighbors of DR, subnet mask of link); confined to local area only
Summary LSA
LSA Type-3; describes summarized info of links from one area into an adjacent area; created by ABRs; confined to local area only, but other ABRs may modify and continue to forward
Data Link Layer
Layer 2 of the OSI reference model, it ensures the trustworthy transmission of data across a physical link and is primarily concerned with physical addressing, line discipline, network topology, error notification, ordered delivery of frames, and flow control. The IEEE has further segmented this layer into the MAC sublayer and the LLC sublayer. Also known as the Link layer. Can be compared somewhat to the Data Link control layer of the SNA model
Application
Layer responsible for File, print, message, database, and application services.
Physical
Layer were media exists
Puts you in the auxiliary interface configuration mode
Line aux
Puts you in console configuration mode
Line console 0
Puts you in VTY (Telnet) interface configuration mode
Line vty
Trunk Link
Link used between switches and from some servers to the switches; carry info about many VLANs. (Access links are used to connect host devices to a switch and carry only VLAN information that the device is a member of)
Stops console messages from overwriting your command-line input
Logging synchronous
Host Address
Logical address configured by an administrator or server on a device. Logically identifies this device on an internetwork
Neighbor Discovery Protocol (NDP)
Makes use of new ICMPv6 message types (neighbor solicitation; neighbor advertisement; router solicitation; router advertisement)
Distribution Layer
Middle layer of the Cisco three-layer hierarchical model, which helps you design, install, and maintain Cisco hierarchical networks; the point where access layer devices connect. Routing is performed at this layer.
It uses a shared logical bus topology, so if there are more customers, each customers gets less bandwidth. It is also more susceptible to security risks.
Name 2 major disadvantages of Cable access.
Simple Mail Transfer Protocol (SMTP), Internet Message Access Protocol version 4 (IMAP4), Post Office Protocol 3 (POP3), File Transfer Protocol (FTP), and Hypertext Transfer Protocol (HTTP)
Name 5 common network protocols.
Session Layer
OSI Layer 5; responsible for creating, managing, and terminating sessions between applications and overseeing data exchange between Presentation layer entities; Helps establish session with reserved port numbers; Session identifier is assigned; Tracks connections between hosts and remote computers/servers; Well-known ports (Ranges from 0 to 1023; Port numbers used by well-known services; Examples: HTTP(80), HTTPS(443), DNS(53), FTP(20,21), TELNET(23), etc.); Registered ports (Reserved for the applications; Ranges from 1024 to 65535); Ephemeral ports
Applications Layer
OSI Layer 7; Interacts with the user applications (Firefox, Outlook, etc.); Provides initial network connection for user applications; Manages the application connections between hosts
Collision Domain
One device sends a packet on a network segment and every other device on the same segment is forced to process it.
Access Layer
One of the layers in Cisco's three-layer hierarchical model; provides users with access to the internetwork; where users gain access to the network and where Cisco recommends users plug into switches, which break up collision domains; switches are used to break up Ethernet networks at this layer
Multicast
One to a group
Check the workstation TCP/IP configuration.
Only one workstation on a particular network cannot reach the Internet. What is the first troubleshooting step if the divide-and-conquer method is being used?
The address was obtained from a DHCP server.
Open the PT ActivityView in a new window. Perform the tasks in the activity instructions and then answer the question or complete the task. How does PC0 obtain its IP address?
Dedicated Leased Lines
P2P; always up; up to 45 Mbps; uses PPP or HDLC
Link Control Protocol (LCP)
PPP must negotiate a connection; moves through a series of req'd steps prior to transport of user data; LCP designed to establish, configure, and test data link connections for use by PPP authentication; state events and transitions can be monitored in real-time with "debug ppp negotiations"
IOS Initial Configuration Commands
Prevent syslog & event messages from interrupting CLI input: Router(config-line)# logging synchronous Prevent DNS resolution attempt for mis-typed commands: Router(config)# no ipdomain-lookup Configure descriptive device name: Router(config)# hostname Lab-1-Rtr Configure informative banner: Router(config)# banner motd Add IPv4 address to an interface: Router(config-if)#ipaddress <address><mask>; Router(config-if)# no shutdown
Frame
Protocol Data Unit encapsulation at the Data Link layer of the OSI reference model. Encapsulates packets from the Network layer and prepares the data for transmission on a network medium.
Address Resolution Protocol (ARP)
Protocol that traces IP addresses to MAC addresses Used to resolve Layer-2 address of hosts on same LAN; Broadcast-based; Proxy ARP (Optional feature on routers and Wi-Fi access points; Router replies on behalf of hosts)
show ip interface brief
Refer to the exhibit. Fill in the blank. Do not use abbreviations. What command does a technician issue on a switch to display the exhibited output?
3
Refer to the exhibit. Fill in the blank. A packet leaving PC-1 has to traverse _____ hops to reach PC-4.
U Reference Point
Reference point between a TE1 and an ISDN network. This type of reference point understands ISDN signaling techniques and uses a 2-wire connection
Classless Routing
Routing that sends subnet mask information in the routing updates. This type of routing allows Variable-Length Subnet Mask (VLSM) and supernetting. Routing protocols that support this routing are RIP version 2, EIGRP, and OSPF
IOS Saving and Deleting Configurations
Save current Running Configuration: Router# copy running-configstartup-config OR Router# write memory Setting a router back to factory defaults: Step-1: Delete startup configuration: Router# erase startup-config OR Router# write erase; Step-2: Reload the router: Router# reload
Encrypts the user mode and enable password
Service password-encryption
Bandwidth
Sets the bandwidth on a serial interface
Shows the DTE or DCE status of an interface
Show controllers s 0
Shows the statistics of interface serial 0
Show interface s0
RIP next generation (RIPng)
Similarities with RIPv2 for IPv4 (distance-vector, radius of 15 hops, split horizon); IPv6 prefix, next-hope IPv6 address; uses the multicast group FF02::9, the all-rip-routers multicast group, as the destination address for RIP updates; can create multiple, named, RIP processes within a single router RIPng Verification: router# show ipv6 rip database; router# show ipv6 route rip; router# show ipv6 protocols RIPng, enabling: router(config)# ipv6 unicast routing; router(config-if)# ipv6 rip <name> enable RIPng, options: router(config)# ipv6 router rip <name> (redistribution, route filtering, changing of default values, etc.)
Binding
Software that maps to another layers' protocols and is specifically designed to be deployed there will handle additional functions.
Any
Specifies any host or any network; same as the 0.0.0.0 255.255.255.255 command
Challenge Authentication Protocol (CHAP)
Supported on lines using PPP encapsulation, it is a security feature that identifies the remote end, helping keep out unauthorized users. After it is performed, the router or access server determines whether a given user is permitted access. It is a newer, more secure protocol than PAP
Switch Fabric
Term used to identify a layer-2 switched internetwork with many switches
Changes your history size from the default of 10 up to 256
Terminal history size
Basic Rate Interface
The ISDN interface that facilitates circuit-switched communication between video, data, and voice; it is made up of two B channels (64Kbps each) and one D channel (16Kbps)
Basic Rate Interface (BRI)
The ISDN interface that facilitates circuit-switched communication between video, data, and voice; it is made up of two B channels (64Kbps each) and one D channel (16Kbps).
Nondesignated Port
The Spanning-Tree Protocol tells a port on a layer-2 switch to stop transmitting and creating a network loop. Only designated ports can send frames
Spanning-Tree Protocol (STP)
The bridge protocol (IEEE 802.1d) that enables a learning bridge to dynamically avoid loops in the network topology by creating a spanning tree using the spanning-tree algorithm. Spanning-tree frames called bridge protocol data units (BPDUs) are sent and received by all switches in the network at regular intervals. The switches participating in the spanning tree don't forward the frames; instead, they're processed to determine the spanning-tree topology itself. Cisco Catalyst series switches use STP 802.1d to perform this function
Half Duplex
The capacity to transfer data in only one direction at a time between a sending unit and receiving unit
Full Duplex
The capacity to transmit information between a sending station and a receiving unit at the same time
Auxiliary Port
The console port on the back of Cisco routers that allows you to dial the router and make console configuration settings
Protocol Data Unit (PDU)
The final, structured data unit created by an OSI Layer; PDUs created at one layer are meant to be read by the same layer on receiving device
Cisco Internetwork Operating System (IOS)
The kernel of the Cisco line of routers and switches that supplies shared functionality, scalability, and security for all products under its CiscoFusion architecture
Central Office (CO)
The local telephone company office where all loops in a certain area connect and where circuit switching of subscriber lines occurs
Physical Layer
The lowest layer—Layer 1—in the OSI reference model, it is responsible for converting data packets from the Data Link layer (Layer 2) into electrical signals; this layer's protocols and standards define, for example, the type of cable and connectors to be used, including their pin assignments and the encoding scheme for signaling 0 and 1 values
Simplex
The mode at which data or a digital signal is transmitted; this is a way of transmitting in only one direction
Collision Domain
The network area in Ethernet over which frames that have collided will spread. Collisions are propagated by hubs and repeaters, but not by LAN switches, routers, or bridges
Demarcation (demarc)
The point between the customer premises equipment (CPE) and the telco's carrier equipment, where the telco's responsibility ends, and the customer's begins
Point-to-Point Protocol (PPP)
The protocol most commonly used for dialup Internet access, superseding the earlier SLIP. Its features include address notification, authentication via CHAP or PAP, support for multiple protocols, and link monitoring. It has two layers: the Link Control Protocol (LCP) establishes, configures, and tests a link; and then any of various Network Control Programs (NCPs) transport traffic for a specific protocol suite, such as IPX.
Broadcast Domain
The set of all devices on a network segment which are allowed to "hear" all broadcasts sent to that specific segment.
Telnet
The standard terminal emulation protocol within the TCP/IP protocol stack. Method of remote terminal connection, enabling users to log in on remote networks and use those resources as if they were locally connected; defined in RFC 854
Holddown
The state a route is placed in so that routers can neither advertise the route nor accept advertisements about it for a defined time period; used to surface bad information about a route from all routers in the network. A route is generally placed in [TERM] when one of its links fails
Encapsulation
The technique used by layered protocols in which a layer adds header information to the protocol data unit (PDU) from the layer above. As an example, in Internet terminology, a packet would contain a header from the Physical layer, followed by a header from the Network layer (IP), followed by a header from the Transport layer (TCP), followed by the application protocol data
Link-Local Addresses
These addresses are assigned automatically as an IPv6 host comes online; similar to the 169.254.x.x address of IPv4; always begin with FE80::/10; last 64 bits is the 48-bit MAC address with FFFE inserted in the middle
Terminal Equipment 2 (TE2)
These devices do not understand ISDN signaling techniques, and a terminal adapter must be used to convert the signaling
Poison Reverse Updates
These update messages are transmitted by a router back to the originator (thus ignoring the split-horizon rule) after route poisoning has occurred. Typically used with DV routing protocols in order to overcome large routing loops and offer explicit information when a subnet or network is not accessible (instead of merely suggesting that the network is unreachable by not including it in updates)
IP Address
This is an address uniquely identifying any device (host) on the Internet (or any TCP/IP network). Each address consists of four octets (32 bits), represented as decimal numbers separated by periods (a format known as "dotted-decimal"). Every address is made up of a network number, an optional subnetwork number, and a host number. The network and subnetwork numbers together are used for routing, while the host number addresses an individual host within the network or subnetwork. The network and subnetwork information is extracted from the IP address using the subnet mask. There are five classes of IP addresses (A-E), which allocate different numbers of bits to the network, subnetwork, and host portions of the address
Backward Explicit Congestion Notification/BECN
This is the bit set by a Frame Relay network in frames moving away from frames headed into a congested path. A DTE that receives frames with [TERM] may ask higher-level protocols to take necessary flow control measures
Tab
To save time, IOS commands may be partially entered and then completed by typing which key or key combination?
C • internal
To which part of the network does the wireless access point part of a Linksys integrated router connect? A • DMZ B • external C • internal D • a network other than the wired network
True
True or False, each port on a switch is its own collision domain.
True
True or False, only routers break up broadcast domains by default.
Random Access Memory (RAM)
Type of computer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes; Used by all computers to store information. Cisco routers use [TERM] to store packet buffers and routing tables, along with the hardware addresses cache
ASBR-Summary LSA
Type-4; Autonomous System Boundary Router: An area border router placed between an OSPF autonomous system and a non-OSPF network that operates both OSPF and an additional routing protocol, such as RIP. ASBRs must be located in a non-stub OSPF area; advertises the ASBR into remote areas; created by ABRs; allows routers that are not in same area as ASBR to forward traffic to it
External LSA
Type-5; advertises non-OSPF routes into OSPF; created by ASBRs; propagated throughout entire OSPF domain
Console Port
Typically an RJ-45 port on a Cisco router and switch that allows Command-Line Interface capability
Boot ROM
Used in routers to put the router into bootstrap mode. Bootstrap mode then boots the device with an operating system. The ROM can also hold a small Cisco IOS
Extended Setup
Used in setup mode to configure the router with more detail than Basic Setup mode. Allows multiple-protocol support and interface configuration
Node Address
Used to identify a specific device in an internetwork. Can be a hardware address, which is burned into the network interface card or a logical network address, which an administrator or server assigns to the node
BPDU Guard
Usually configured on access ports that lead to hosts; If any BPDU is seen, port goes into err-disabled state Configuration - (config-if)#spanning-tree bpduguard enable; (config)#spanning-tree portfast bpduguard default
Passive
What class of attack monitors unencrypted traffic, looking for such things as clear-text passwords?
a large corporate environment
What environment would be best suited for a two-firewall network design?
Adversary
What general security term is used to describe a person interested in attacking your network?
to display the host routing table Refer to curriculum topic: 6.2.1 The command netstat -r displays the host routing table to verify the routes and costs that a computer uses to communicate to certain networks.
What is the command netstat -r used for?
Ethernet.
What is the de facto standard for LAN-based networks?
DNS server
What resolves a website URL to an IP address?
local delivery
What type of delivery uses data link layer addresses?
ipconfig /renew
Which ipconfig command requests IP configuration from a DHCP server?
bottom-up
Which troubleshooting method begins by examining cable connections and wiring issues?
A. dash D. numbers
Which two characters are allowed as part of the hostname of a Cisco device? (Choose two.) A. dash B. space C. tab D. numbers E. question mark
Any host or user can get a public IPv6 network address because the number of available IPv6 addresses is extremely large.
Why is NAT not needed in IPv6?
to add a password to a Cisco network device
Why would a network administrator use the CLI of the Cisco IOS?
Gateway Load Balancing Protocol (GLBP)
cisco proprietary; provides gateway redundance AND per-host load balancing; AVG (active virtual gateway) in charge of determining host-to-gateway allocations; configured similarly to HSRP
IPv4
classes: A (0.0.0.0 through 127.255.255.255); B: (128.0.0.0 through 191.255.255.255); C: (192.0.0.0 through 223.255.255.255); D: (224.0.0.0 through 239.255.255.255); E: (240.0.0.0 through 255.255.255.255); 127 ranges are considered as loopbacks; 169.254 ranges are considered as APIPA; IP addresses "leased" to a corporation are known as public IP addresses; IP addresses that are unregistered and may overlap from one company to the next, are known as private IP addresses configuration: Router(config-if)# ip address <address><mask>; Verification: Show interface <type><number>, Show ip interface brief
Clears a connection connected via Telnet to your router
clear line
Provides clocking on a serial DCE interface
clock rate
IOS Command Structure
command hierarchy: Router>-User (or EXEC) mode; Router#-Privileged EXEC (or Enable) mode; Configuration modes: Router(config)# -Global Configuration Mode; Router(config-if)# -Interface Configuration Mode; Router(config-router)# -Router Configuration Mode; Usage of Exit, End, Ctrl-Z
Copies a configuration stored on a TFTP host to running-config
config network
Puts you in global configuration mode and changes the runningconfig
config terminal
Tells the router how to boot and to change the configuration register setting
config-register
User Datagram Protocol (UDP)
connectionless Transport layer protocol in the TCP/IP protocol stack that simply allows datagrams to be exchanged without acknowledgements or delivery guarantees, requiring other protocols to handle error processing and retransmission. UDP is defined in RFC 768 connectionless; Unreliable; Protocol number 17
Copies a file from flash memory to a TFTP host
copy flash tftp
Copies the running-config file to the startup-config file; Short for copy running-config startup-config. Places a configuration into NVRAM
copy run start
Copies the running-config file to a TFTP host
copy run tftp
Copies a file from a TFTP host to flash memory
copy tftp flash
Copies a configuration from a TFTP host to the running-config file
copy tftp run
Shows you the call setup and teardown procedures
debug dialer
Shows the lmi exchanges between the router and the Frame Relay switch
debug frame-relay lmi
Provides a summary of the IGRP routing information running on the network
debug ip igrp events
Shows message requests from neighbor routers asking for an update and the broadcasts sent from your router to that neighbor router
debug ip igrp transactions
Sends console messages displaying information about RIP packets being sent and received on a router interface
debug ip rip
Shows the RIP and SAP information as it passes through the router
debug ipx
Shows layer-2 processes
debug isdn q921
Shows layer-3 processes
debug isdn q931
Deletes the contents of NVRAM on a 1900 switch
delete nvram
Tells the BRI line when to drop if no interesting traffic is found
dialer idle-timeout number
Specifies interesting traffic for a DDR link
dialer list number protocol protocol permit/deny
Sets the parameters that describe when the second BRI comes up on a ISDN link
dialer load-threshold number inbound/outbound/either
Used instead of a dialer string to provide more security in an ISDN network
dialer map protocol address name hostname number
Sets the phone number to dial for a BRI interface
dialer-string
Takes you from privileged mode back to user mode
disable
Disconnects a connection to a remote router from the originating router
disconnect
Puts you into privileged mode
enable
Sets the unencrypted enable password
enable password
Sets the encrypted enable secret password. Supersedes the enable password if set
enable secret
Sets the frame type used on an interface
encapsulation
Changes the encapsulation to Frame Relay on a serial link
encapsulation frame-relay
Sets the encapsulation type to the Internet Engineering Task Force (IETF). Connects Cisco routers to off-brand routers
encapsulation frame-relay ietf
Restores the default encapsulation of HDLC on a serial link
encapsulation hdlc
Changes the encapsulation on a serial link to PPP
encapsulation ppp
Deletes the contents of NVRAM on a router
erase startup-config
Disconnects a connection to a remote router via Telnet
exit
Sets the name of a router
hostname
Creates a subinterface
int e0.10
Puts you in interface configuration mode. Also used with show commands
interface
Turns on DNS lookup (which is on by default)
ip domain-lookup
Appends a domain name to a DNS lookup
ip domain-name
Creates a host table on a router
ip host
Sets the IP address of up to six DNS servers
ip name-server
Creates static and default routes on a router
ip route
Applies an IPX access list to an interface
ipx access-group
Applies an inbound IPX SAP filter to an interface
ipx input-sap-filter
Assigns an IPX network number to an interface
ipx network
Applies an outbound IPX SAP filter to an interface
ipx output-sap-filter
Is a Packet Internet Groper used to test IPX packet on an internetwork
ipx ping
Turns on IPX routing
ipx routing
Sets the number that identifies the first DS0 to the ISDN switch
isdn spid1
Sets the number that identifies the second DS0 to the ISDN switch
isdn spid2
Logs you out of your console session
logout
Sets the hardware media type on an interface
media-type
Frame Relay
multipoint technology; legacy tech typically used in service provider end; layer-2 specification; uses same pair of telephone wires for last mile; data placed into frame relay headers; utilizes PVCs (permanent virtual circuits); ATM typically used in core Frame Relay header - 8 bit flag, 16 bit address; variable data; 16 bit FCS; 8 bit flag; 16 bit address breakdown: byte 1 includes DLCI, CIR, EA and byte 2 has DLCI, FECN, BECN, DE and EA Frame relay Multipoint Configuration commands: router(config-if)# encapsulation frame-relay; router(config-if)# ip address <address> <subnet mask>; router(config-if)# end Frame Relay Verification - router# show frame-relay pvc; router# show frame-relay map
Switch
multiport bridge (more ports than a bridge; Mixture of port speeds & types); Forwards frames based on the MAC address table; Separates collision domain; Operates in data link layer; 1) In networking, a device responsible for multiple functions such as filtering, flooding, and sending frames. It works using the destination address of individual frames. Switches operate at the Data Link layer of the OSI model. 2) Broadly, any electronic/mechanical device allowing connections to be established as needed and terminated if no longer necessary
Tells the routing protocol what network to advertise
network
Turns off CDP on an individual interface
no cdp enable
Turns off CDP completely on a router
no cdp run
Turns off the dynamic IARP used with Frame Relay. Static mappings must be configured
no inverse-arp
Turns off DNS lookup
no ip domain-lookup
Removes a hostname from a host table
no ip host
Removes a static or default route
no ip route
Turns on an interface
no shutdown
Tests IP connectivity to remote device
ping
Tells PPP to use CHAP authentication
ppp authentication chap
Tells PPP to use PAP authentication
ppp authentication pap
EIGRP External
route that was previously learned via some non-EIGRP method and injected into EIGRP with "redistribute" command; admin distance = 170
Turns on IP IGRP routing on a router
router igrp as
Adds a second IPX network on the same physical interface
secondary
Shows all the access lists configured on the router
show access-list
Shows only access-list 110
show access-list 110
Displays the CDP timer and holdtime frequencies
show cdp
Same as show cdp neighbor detail, but does not work on a 1900 switch
show cdp entry *
Shows the individual interfaces enabled with CDP
show cdp interface
Shows the CDP packets sent and received on a device and any errors
show cdp traffic
shows the number of times the dialer string has been reached, the idle-timeout values of each B channel, the length of call, and the name of the router to which the interface is connected
show dialer
Shows the files in flash memory
show flash
Sets the LMI type on a serial interface
show frame-relay lmi
Shows the static and dynamic Network layer-to-PVC mappings
show frame-relay map
Shows the configured PVCs and DLCI numbers configured on a router
show frame-relay pvc
Shows you the last 10 commands entered by default
show history
Shows the contents of the host table
show hosts
Shows only the IP access lists
show ip access-list
Shows which interfaces have IP access lists applied
show ip interface
Shows the routing protocols and timers associated with each routing protocol configured on a router
show ip protocols
Displays the IP routing table
show ip route
Shows your connections via Telnet to remote devices
show sessions
Displays the startup-config file; Short for show startup-config. Shows the backup configuration stored in NVRAM
show start
Shows you your configured history size
show terminal
Displays the IOS type and version as well as the configuration register
show version
Puts an interface in administratively-down mode
shutdown
Finishes typing a command for you
tab
Connects, views, and runs programs on a remote device; tests IP connectivity and configures a router
telnet
Creates a TFTP-server host for a router system image that is run in flash
tftp-server system ios-name
Tests a connection to a remote device and shows the path it took through the internetwork to find the remote device; Tests IP connectivity
trace
Tells the IGRP routing protocol to share links inversely proportional to the metrics
traffic-share balanced
Tells the IGRP routing process to use routes that have only minimum costs
traffic-share min
Optical Carriers (OCs)
use fiber optics; 3 bundled DS3/T3's at 155.52 Mbps
Creates usernames and passwords for authentication on a Cisco router
username name password password
Digital Subscriber Line (DSL)
uses same pair of telephone wires to deliver voice and data; slower than cable; uses different frequencies to separate voice/data
Controls the load balancing between the best metric and the worst acceptable metric
variance
192.168.1.1
what IP address would computers use as their default gateway when on a local wireless network using DHCP Configurtion?
Enhanced interior Gateway Routing Protocol (EIGRP)
Open standard; Hybrid IGP (characteristics of both Link State and Distance Vector); metric based from link bandwidth & delay; supports manual and automatic summarization; supports MD5 authentication; supports unequal cost load-balancing; Distance is the metric EIGRP uses, gotten from formula; hello's go out every 10 seconds Authentication - Supports MD5 authentication; Uses a combination of key-chain and key-string with authentication password; More secure than plain-text authentication; Can be used with multiple time-based key-chains; Router# debug eigrppackets Authentication, configuration - Global: Router(config)# key-chain <name>; Router(config-keychain)# key <key-id>; Router(config-keychain-key)# key-string <password>; Router(config-keychain-key)# send-lifetime <duration>; Router(config-keychain-key)# accept-lifetime <duration>; Router(config-keychain-key)# end; Interface: Router(config-if)# ipauthentication eigrp<AS-Number> mode md5, Router(config-if)# ipauthentication key-chain eigrp<AS-Number> <key-chain name> Configuration commands: router(config)# router eigrp <AS-number>; router(config-router)# no auto-summary; router(config-router)# network <network-id>; router(config-router)# end; AS number should match between EIGRP routers
Dynamic Host Configuration Protocol (DHCP)
Operates in application layer; provides dynamic method of leasing an IP address to host; uses UDP ports 67/68; can be useful for a small network where a dedicated DHCP server is not available (configuring router as DHCP server) Configuration - router(config)# service dhcp; router(config)# ip dhcp pool <pool-name>; router(config-dhcp)# network <network-id>; router(config-dhcp)# default-router <default gateway>; router(config-dhcp)#dns-server <dns-server address>; router(config-dhcp)# lease <duration>; router(config-dhcp)#end Exclude list: router(config)# ip dhcp excluded-address <start-ip> <end-ip> Verification: router# show ip dhcp binding
Class B Network
Part of the Internet Protocol hierarchical addressing scheme. Class B networks have 16 bits for defining networks and 16 bits for defining hosts on each network
Class C Network
Part of the Internet Protocol hierarchical addressing scheme; have 24 bits for defining networks and only 8 bits for defining hosts on each network
Class A Network
Part of the Internet Protocol hierarchical addressing scheme; have only 8 bits for defining networks and 24 bits for defining hosts on each network
B. VTY interface C. privileged EXEC mode E. console interface
Passwords can be used to restrict access to all or parts of the Cisco IOS. Select the modes and interfaces that can be protected with passwords. (Choose three.) A. boot IOS mode B. VTY interface C. privileged EXEC mode D. Ethernet interface E. console interface F. router configuration mode
Hubs
Physical-layer devices that are really just multiple port repeaters. When an electronic digital signal is received on a port, the signal is reamplified or regenerated and forwarded out all segments except the segment from which the signal was received
IP Routing
Process of forwarding packets between networks; Basic components needed to route include Routable Packet (IPv4, IPv6, etc), Network address, Subnet mask, Next Hop, Metric; Types of routes include connected, static and dynamic; Router will only use routes with reachable "next hops"; Routers will only use the "best" routes; Routes must be "believable" (how do I know this route is still good?); Router will only accept routes that match its own, active protocols (No IPv6 routes accepted if router not an IPv6 host)
B • It reassembles the frame with different MAC addresses than the original frame.
Refer to the graphic. What does the router do after it determines that a data packet from Network 1 should be forwarded to Network 2? A • It sends the data packet as it was received. B • It reassembles the frame with different MAC addresses than the original frame. C • It reassembles the data packet with different IP addresses than the original data packet. D • It reassembles both the packet and the frame with different destination IP and MAC addresses.
Registered ports
Reserved for the applications; Ranges from 1024 to 65535
Internet Protocol version 4
Resides at OSI Layer-3 (Network Layer); Connectionless; 32-bit addressing system; Logical address for a network defined by IANA; these addresses are comprised of 4 octets; Dotted decimal notation is used to segment the octet
EIGRP Internal
Route that was originated within Autonomous System with the "network" command; admin distance = 90
Puts you in router rip configuration mode; Turns on IP RIP routing on a router
Router rip
EIGRPv6
Similarities to IPv4 EIGRP: most packets transmitted via multicast; same metric formula; utilizes same msg types (hello, update, ack, etc); uniqueness of EIGRPv6: packets sent to FF02::A; peers w/ link-local address of neighbors; next-hop address is link-local of peer Verification - Router# show ipv6 eigrp neighbor; Router# show ipv6 eigrp topology; Router# show ipv6 route eigrp; Router# show ipv6 protocols EIGRPv6, applying: router(config-if)# ipv6 eigrp <number> EIGRPv6, enabling: router(config)# ipv6 unicast routing; router(config)# ipv6 router eigrp <number>; router(config)# no shutdown; router(config)# router-id x.x.x.x; router(config-router)# exit
MAC-Address Table
Switch MAC Learning (Based on Source MAC Address; Addresses age out after inactivity-timer); Switching forwarding (Based on Destination MAC; Broadcast/Multicast/Unknown flooding; All ports initially in one, large, broadcast domain)
Access Port
Switchport configured for only a single broadcast domain (VLAN) Configuring - Switch(config)# interface <interface>; Switch(config-if)# switchportmode access; Switch(config-if)# switchportaccess vlan<vlan-id>
Data Communications Equipment (DCE)
The mechanisms and links of a communications network that make up the network portion of the user-to-network interface, such as modems; supplies the physical connection to the network, forwards traffic, and provides a clocking signal to synchronize data transmission between devices
Core Layer
Top layer in the Cisco three-layer hierarchical model, which helps you design, build, and maintain Cisco hierarchical networks; passes packets quickly to distribution-layer devices only. No packet filtering should take place at this layer
True
True or False, routers filter the network based on the network layer using information like IP addresses.
True
True or False, switches create separate collision domains within a single broadcast domain. Routers provide a separate broadcast domain for each interface.
True
True or False, you create an internetwork when you connect two or more networks via a router and configure a logical network addressing scheme with a protocol such as IP or IPv6.
False
True or false, routers forward broadcasts by default.
cdp run
Turns on CDP on a router
Inter-VLAN Routing
Two ways to configure (Router-on-a-stick model, Routing with SVI); A router is usually configured using sub-interface; Single point of failure; Configuring a trunk interface that is connected to the router (Switch(config-if)# switchportmode trunk); Configuring sub-interface for respective VLANs (Router(config-sub-if)# encapsulation dot1q <vlan-id>, Router(config-sub-if)# ipaddress <address> <subnet mask>); Multilayer Switches can route between VLANs; Requires a separate SVI for each VLAN (Each SVI needs a physical port (Access or Trunk) in that VLAN); Hosts point to IP address on SVI as their default gateway
Static Routing
Typically used in the small network; Info on destination prefix and gateway are required; Can increase administrative overhead; No dynamic fail-over; Preferred over dynamic routing protocols because of lower administrative distance; Configuration (next-hop): Router(config)#ip route <destination-network> <destination subnet mask> <next-hop>; Configuration (outgoing interface): Router(config)#iproute <destination-network> <destination subnet mask> <outgoing interface>; Verification: Router# show ip route; Router# show ip route static; Router# show running-config| include ip route; Router# show ip protocol; Router# show ip route <prefix> <mask>
Domain Name Service (DNS)
Used by computers to resolve host names to IP addresses; Typically uses UDP port 53; DNS server responds to DNS requests (Host sends DNS A-Record query; DNS server responds with A-Record query response)
Route Poisoning
Used by various DV routing protocols in order to overcome large routing loops and offer explicit information about when a subnet or network is not accessible (instead of merely suggesting that the network is unreachable by not including it in updates). Typically, this is accomplished by setting the hop count to one more than maximum
Routing Metric
Used for best path selection process; IGPs use metric for shortest path calculation; Lower value is preferred; Depends on the routing protocol architecture (EIGRP metric = composite formula utilizing link bandwidth + delay; RIP metric = hop count; OSPF metric = link bandwidth)
Discard Eligibility (DE)
Used in Frame Relay networks to tell a switch that a frame can be discarded if the switch is too busy. The DE is a field in the frame that is turned on by transmitting routers if the Committed Information Rate (CIR) is oversubscribed or set to 0
Application Specific Integrated Circuits (ASICs)
Used in layer-2 switches to make filtering decisions; looks in the filter table of MAC addresses and determines which port the destination hardware address of a received hardware address is destined for. The frame will be allowed to traverse only that one segment. If the hardware address is unknown, the frame is forwarded out all ports
Data Link Connection Identifier (DLCI)
Used to identify virtual circuits in a Frame Relay network; works as a layer 2 address in frame relay; works like a MAC address in a LAN; 10-bit value that ranges from 0 to 1023, where 0-15 and 1007-1023 are reserved
Loop Guard
Used to prevent loops caused by unidirectional link; Uses BPDU keepalive to detect unidirectional link; BPDUs should always be received on a Blocked port; If BPDUs don't arrive, normally convert to a Designated port; Configured with spanning-tree guard loop interface-specific command
VLAN Trunking Protocol (VTP)
Used to update switches in a switch fabric about VLANs configured on a [TERM] server; can be a [TERM] server, client, or transparent device. Servers update clients. Transparent devices are only local devices and do not share information with [TERM] clients; send VLAN information down trunked links only
Basic Management Setup
Used with Cisco routers when in setup mode. Only provides enough management and configuration to get the router working so someone can telnet into the router and configure it
R Reference Point
Used with ISDN networks to identify the connection between an NT1 and an S/T device. The S/T device converts the 4-wire network to the two-wire ISDN standard network
Wildcard
Used with access-list, supernetting, and OSPF configurations; designations used to identify a range of subnets
T Reference Point
Used with an S reference point to change a 4-wire ISDN network to a 2-wire ISDN network
Circuit Switching
Used with dial-up networks such as PPP and ISDN. Passes data, but needs to set up the connection first—just like making a phone call
Circuit Switching
Used with dial-up networks such as PPP and ISDN. Passes data, but needs to set up the connection first—just like making a phone call; POTS (plain old telephone service); ISDN (integrated Services Digital Network); typically use modem which transfers digital/analog data; method of establishing a WAN that didn't exist before and it goes down after; takes time to establish circuit
Port Security
Used with layer-2 switches to provide some security. Not typically used in production because it is difficult to manage. Allows only certain frames to traverse administrator-assigned segments; Used to limit access to a port based on MAC address or quantity of connected devices; Can be configured on static access and trunk ports (but not "dynamic" ports); A secure port cannot be: Destination port for SPAN, Port-channel, Private VLAN port Enabling port security: Switch(config-if)# switchportport-security Limiting number of MAC addresses: Switch(config-if)# switchportport-security maximum <number>, Switch(config-if)# switchportport-security mac-address <MAC> <sticky> Configuring recovery interval: Switch(config)# errdisablerecovery psecure-violation, Switch(config)# errdisablerecovery interval <interval in sec> Verifying Port Security: Switch# Show port-security, Switch# Show port-security interface <intf-type> <intf-number>
Designated Port
Used with the Spanning-Tree Protocol (STP) to designate forwarding ports (ports that can send frames). If there are multiple links to the same network, STP will shut a port down to stop network loops
Root Bridge
Used with the Spanning-Tree Protocol to stop network loops from occurring; elected by having the lowest bridge ID. The bridge ID is determined by the priority (32,768 by default on all bridges and switches) and the main hardware address of the device; determines which of the neighboring layer-2 devices' interfaces become the designated and nondesignated ports
Network Address
Used with the logical network addresses to identify the network segment in an internetwork. Logical addresses are hierarchical in nature and have at least two parts: network and host. An example of a hierarchical address is 172.16.10.5, where 172.16 is the network and 10.5 is the host address
Address Learning
Used with transparent bridges to learn the hardware addresses of all devices on an internetwork. The switch then filters the network with the known hardware (MAC) addresses
Split Horizon
Useful for preventing routing loops, a type of distance-vector routing rule where information about routes is prevented from leaving the router interface through which that information was received
High-Level Data Link Control (HDLC)
Using frame characters, including checksums, it designates a method for data encapsulation on synchronous serial links and is the default encapsulation for Cisco routers; a bit-oriented synchronous Data-Link layer protocol created by ISO and derived from SDLC; most of its vendor implementations (including Cisco's) are proprietary
Dynamic Routing
Usually configured in large/ISP networks; Can be categorized into two sections (IGP, Interior Gateway Protocol, Protocol that works within the Autonomous System Number; EGP, Exterior Gateway Protocol, Protocol that interconnects multiple Autonomous System Numbers); Dynamic failover
Toll Network
WAN network that uses the Public Switched Telephone Network (PSTN) to send packets
Computers, networking, and media.
What 3 component categories do you need to build a network?
Cost, security, speed, topology, scalability, reliability, and availability.
What 7 characteristics should be considered when creating or maintaining a network?
C • traffic filtering
What access-point feature allows a network administrator to define what type of data can enter the wireless network? A • encryption B • hacking block C • traffic filtering D • MAC address filtering E • authentication
It uses coaxial copper and fiber connections, and it supports higher rates than DSL.
What are 2 characteristics of Cable access?
They are not available at all locations, and they are difficult to set up and troubleshoot,
What are 2 downsides to using cell-switched services?
E-mail, FTP, and web applications.
What are 3 common networking applications?
DSL provides speeds up to a few megabits per second (Mbps), it costs much less than a typical WAN circuit from the carrier, it supports both voice and video, and doesn't require a dial-up connection.
What are 4 characteristics of DSL?
Cable and DSL modems, carrier switches, CSU/DSU's, firewalls, modems, NT1's, and routers.
What are 7 networking devices that are used in WAN connections?
To connect networking devices that are in a very close geographic area.
What are Local area networks (LANs) used for?
To connect LAN's together, even when they are separated by a large distance.
What are Wide Area Networks (WAN's) used for?
Specialized network components that typically provide many security functions.
What are network security appliances?
protocols developed by organizations who have control over their definition and operation
What are proprietary protocols?
Coverage is limited to about 18,000 feet, and it is not available in all areas.
What are the 2 main disadvantages of DSL?
Circuit-switched, cell-switched, packet-switched, and dedicated connections.
What are the 4 basic type of WAN connections or circuits?
D • 64 bit E • 128 bit
What are the two WEP key lengths? (Choose two.) A • 8 bit B • 16 bit C • 32 bit D • 64 bit E • 128 bit
C • anytime, anywhere connectivity D • easy and inexpensive to install F • ease of adding additional devices
What are three advantages of wireless over wired technology? (Choose three.) A • more secure B • longer range C • anytime, anywhere connectivity D • easy and inexpensive to install E • ease of using licensed air space F • ease of adding additional devices
C • mobility D • reduced installation time
What are two benefits of wireless networking over wired networking? (Choose two.) A • speed B • security C • mobility D • reduced installation time E • allows users to share more resources F • not susceptible to interference from other devices
directing data packets to destination hosts on other networks providing end devices with a unique network identifier Refer to curriculum topic: 6.1.1 The network layer is primarily concerned with passing data from a source to a destination on another network. IP addresses supply unique identifiers for the source and destination. The network layer provides connectionless, best-effort delivery. Devices rely on higher layers to supply services to processes.
What are two functions that are provided by the network layer? (Choose two.)
A. Hosts can connect to the network and get an IP address without manual configuration.
What benefit does DHCP provide to a network? A. Hosts can connect to the network and get an IP address without manual configuration. B. Duplicate addresses cannot occur on a network that issues dynamic addresses using DHCP and has static assignments. C. Hosts always have the same IP address and are therefore always reachable. D. DHCP allows users to refer to locations by a name rather than an IP address.
B • a change of the default IP address
What best practice relates to wireless access point security? A • activation of a popup stopper B • a change of the default IP address C • an update in the antivirus software definitions D • physically securing the cable between the access point and client
A. ipconfig
What command can be used on a Windows PC to see the IP configuration of that computer? A. ipconfig B. show interfaces C. show ip interface brief D. ping
nslookup
What command is used to determine if a DNS server is providing name resolution?
tracert
What command is used to determine the location of delay for a packet traversing the Internet?
(config)# service password-encryption
What command will prevent all unencrypted passwords from displaying in plain text in a configuration file?
A. Each IP address must be unique within the local network.
What criterion must be followed in the design of an IPv4 addressing scheme for end devices? A. Each IP address must be unique within the local network. B. Each IP address must match the address that is assigned to the host by DNS. C. Each IP address needs to be compatible with the MAC address. D. Each local host should be assigned an IP address with a unique network component.
SOHO
What describew users working from home?
B • the router interface closest to the computer
What device is typically used as the default gateway for a computer? A • a server hosted by the ISP B • the router interface closest to the computer C • a server managed by a central IT department D • the switch interface that connects to the computer
Protocols are used to implement applications.
What do Protocols do?
How network components communicate across the physical topology.
What does a logical topology describe?
How network components are connected.
What does a network topology define?
How network components are physically cabled together.
What does a physical topology describe?
Sets an IP address on an interface
What does the "ip address" command do?
C • speed of transmission
What does the 100 mean when referencing the 100BASE-T Ethernet standard? A • type of cable used B • type of data transmission C • speed of transmission D • type of connector required E • maximum length of cable allowed
C • The device is interoperable with other devices of the same standard that also display the Wi-Fi logo.
What does the Wi-Fi logo indicate about a wireless device? A • IEEE has approved the device. B • The device is interoperable with all other wireless standards. C • The device is interoperable with other devices of the same standard that also display the Wi-Fi logo. D • The device is backwards compatible with all previous wireless standards.
A • a large corporate environment
What environment would be best suited for a two-firewall network design? A • a large corporate environment B • a home environment with 10 or fewer hosts C • a home environment that needs VPN access D • a smaller, less congested business environment
The host portion of the IP addresses will be different.
What happens when two devices on the same subnet are communicating?
source and destination IP addresses
What information is contained in an IP header?
B • keeps broadcasts contained within a local network
What is a benefit of having a router within the distribution layer? A • prevents collisions on a local network B • keeps broadcasts contained within a local network C • controls which hosts have access to the network D • controls host-to-host traffic within a single local network
fostering competition among device and software vendors by enforcing the compatibility of their products
What is a benefit of using a layered model for network communications?
to describe the ordered and reliable delivery of data between source and destination
What is a function of Layer 4 of the OSI model?
D • exploits vulnerabilities with the intent of propagating itself across a network
What is a major characteristic of a Worm? A • malicious software that copies itself into other executable programs B • tricks users into running the infected software C • a set of computer instructions that lies dormant until triggered by a specific event D • exploits vulnerabilities with the intent of propagating itself across a network
A network is all of the components involved in connecting computers and applications across small and large distances to increase productivity and give easy access to information.
What is a network?
D • It enables the user to set more specific security access levels.
What is a reason for disabling simple file sharing? A • It enables the user to map a remote resource with a local drive. B • It enables the user to share all files with all users and groups. C • It enables the user to share printers. D • It enables the user to set more specific security access levels.
A. All passwords in the configuration are not shown in clear text when viewing the configuration.
What is a result of using the service password-encryption command on a Cisco network device? A. All passwords in the configuration are not shown in clear text when viewing the configuration. B. The command encrypts the enable mode password. C. The command encrypts the banner message. D. A network administrator who later logs into the device will be required to enter an administrator password in order to gain access to the Cisco device.
It informs network devices to maintain the same path for real-time application packets.
What is a service provided by the Flow Label field of the IPv6 header?
A. if there is connectivity with the destination device
What is a user trying to determine when issuing a ping 10.1.1.1 command on a PC? A. if there is connectivity with the destination device B. the path that traffic will take to reach the destination C. what type of device is at the destination D. if the TCP/IP stack is functioning on the PC without putting traffic on the wire
B • spam
What is a widely distributed approach to marketing on the Internet that advertises to as many individual users as possible via IM or e-mail? A • brute force B • spam C • spyware D • tracking cookies
A client host and a server running different operating systems can successfully exchange data.
What is an advantage of network devices using open standard protocols?
It prevents changes in one layer from affecting other layers.
What is an advantage of the use of layers in the OSI reference model?
Products from different manufacturers can interoperate successfully.
What is an advantage of using standards to develop and implement protocols?
Two routers connected across a dedicated WAN circuit.
What is an example of a point-to-point topology?
the privileged executive mode password
What is encrypted with the enable secret command?
B • It identifies missing security updates on a computer.
What is one function that is provided by a vulnerability analysis tool? A • It provides various views of possible attack paths. B • It identifies missing security updates on a computer. C • It identifies wireless weak points such as rogue access points. D • It identifies all network devices on the network that do not have a firewall installed. E • It identifies MAC and IP addresses that have not been authenticated on the network.
C • Pre-shared keys require an encrypted secret word. Open authentication does not require a secret word.
What is the difference between using open authentication and pre-shared keys? A • Open authentication requires a password. Pre-shared keys do not require a password. B • Open authentication is used with wireless networks. Pre-shared keys are used with wired networks. C • Pre-shared keys require an encrypted secret word. Open authentication does not require a secret word. D • Pre-shared keys require a MAC address programmed into the access point. Open authentication does not require this programming.
N x (N-1) divided by 2, where N is the number of locations.
What is the formula that is used to determine the number of links needed to fully mesh a WAN?
A • detects transmission errors
What is the function of the FCS field in an Ethernet frame? A • detects transmission errors B • provides timing for transmission C • contains the start of frame delimiter D • indicates which protocol will receive the frame
protocol data unit
What is the general term that is used to describe a piece of data at any layer of a networking model?
EIA
What is the international standards and trade organization for electronics organizations that is best known for its standards related to electrical wiring, connectors, and the 19-inch racks used to mount networking equipment.
If the center of the star fails, no devices can communicate. Overcome by using an extended star topology that is multiple interconnected star topologies.
What is the main disadvantage of a star topology, and how can it be overcome?
IEEE
What is the professional organization for those in the electrical engineering and electronics fields that creates and maintains standards affecting a wide range of industries including telecommunications, and networking?
E • identifies the device that allows local network computers to communicate with devices on other networks
What is the purpose of a default gateway? A • physically connects a computer to a network B • provides a permanent address to a computer C • identifies the network to which a computer is connected D • identifies the logical address of a networked computer and uniquely identifies it to the rest of the network E • identifies the device that allows local network computers to communicate with devices on other networks
D • They are used to determine the network that the host is located on.
What is the purpose of logical addresses in an IP network? A • They identify a specific NIC on a host device. B • They are used to determine which host device accepts the frame. C • They provide vendor-specific information about the host. D • They are used to determine the network that the host is located on. E • They are used by switches to make forwarding decisions.
providing the rules required for a specific type of communication to occur
What is the purpose of protocols in data communications?
flow control
What method can be used by two computers to ensure that packets are not dropped because too much data is being sent too quickly?
ISO
What organization developed the OSI reference model that is used in networking?
acceptable use
What part of the security policy states what applications and usages are permitted or denied?
C • acceptable use
What part of the security policy states what applications and usages are permitted or denied? A • identification and authentication B • remote access C • acceptable use D • incident handling
Data and applications, printers, network storage components, and backup storage components.
What resources are commonly shared across a network?
Ask the user what URL has been typed and what error message displays.
What should a network administrator do first after receiving a call from a user who cannot access the company web server?
Minimal delay and latency.
What specific requirements are needed for large data transfers for things such as Voice over IP (VOIP) and video Quality of Service (QoS)?
ARP is used to discover the MAC address of any host on the local network.
What statement describes the function of the Address Resolution Protocol?
D • Internet access can be denied for specific days and times.
What statement is true about security configuration on a Linksys integrated router? A • A DMZ is not supported. B • The router is an example of a server-based firewall. C • The router is an example of an application-based firewall. D • Internet access can be denied for specific days and times.
D • encryption
What term describes the encoding of wireless data to prevent intercepted data from being read by a hacker? A • address filtering B • authentication C • broadcasting D • encryption E • passphrase encoding
appliance-based
What term is used to describe a dedicated hardware device that provides firewall services?
D • appliance-based
What term is used to describe a dedicated hardware device that provides firewall services? A • server-based B • integrated C • personal D • appliance-based
protocol stack
What term is used to describe how TCP/IP protocols are layered and interact to format, address, and transmit information across a network?
data encoding message size delivery options
What three functions are defined by network protocols to allow communication between known source and destination IP addresses? (Choose three.)
destination MAC address error-checking information
What three items are contained in an Ethernet header and trailer? (Choose three.)
B • popups
What type of advertising is typically annoying and associated with a specific website that is being visited? A • adware B • popups C • spyware D • tracking cookies
A • Open
What type of authentication does an access point use by default? A • Open B • PSK C • WEP D • EAP
What type of server would use IMAP?
IOS
What will a network administrator use to modify a configuration on a Cisco router?
When redundancy is needed, and the benefit is that in a dual-ring topology, the ring can loop back on itself.
When are dual ring topologies used, and what is the benefit?
upper-layer connection-oriented protocols
When connectionless protocols are implemented at the lower layers of the OSI model, what are usually used to acknowledge the data receipt and request the retransmission of missing data?
Flow Label Refer to curriculum topic: 6.1.4 The Flow Label in IPv6 header is a 20-bit field that provides a special service for real-time applications. This field can be used to inform routers and switches to maintain the same path for the packet flow so that packets will not be reordered.
When transporting data from real-time applications, such as streaming audio and video, which field in the IPv6 header can be used to inform the routers and switches to maintain the same path for the packets in the same conversation?
when the full IOS cannot be found
When would the Cisco IOS image held in ROM be used to boot the router?
DNS server
Whenever e-mail clients send letters, what device is used to translate the domain names into their associated IP addresses?
Carrier networks, such as telephone companies and Internet service providers.
Where are WAN's leased from?
802.11
Which IEEE standard enables a wireless NIC to connect to a wireless AP that is made by a different manufacturer?
differentiated services
Which IPv4 header field is responsible for defining the priority of the packet?
Frame
Which PDU format is used when bits are received from the network medium by the NIC of a host?
E • wireless client
Which WLAN component is commonly referred to as an STA? A • cell B • antenna C • access point D • wireless bridge E • wireless client
DMZ
Which acronym refers to an area of the network that is accessible by both internal, or trusted, as well as external, or untrusted, host devices?
B • DMZ
Which acronym refers to an area of the network that is accessible by both internal, or trusted, as well as external, or untrusted, host devices? A • SPI B • DMZ C • ISR D • ISP
destination MAC address
Which address does a NIC use when deciding whether to accept a frame?
D • destination MAC address
Which address does an NIC use when deciding whether to accept a frame? A • source IP address B • source MAC address C • destination IP address D • destination MAC address E • source Ethernet address
logical address
Which address provides a unique host address for data communications at the internet layer?
DNS
Which application is most likely used to translate www.cisco.com to 198.133.219.25?
show ip interface brief
Which command displays a summary chart of all router interfaces, their IP addresses, and their current operational status?
D • hub
Which device accepts a message on one port and always forwards the message to all other ports? A • modem B • switch C • router D • hub
local router
Which device acts as a gateway to allow hosts to send traffic to remote IP networks?
gateway of last resort Refer to curriculum topic: 6.2.2 A default static route is used as a gateway of last resort to forward unknown destination traffic to a next hop/exit interface. The next-hop or exit interface is the destination to send traffic to on a network after the traffic is matched in a router. The route source is the location a route was learned from.
Which feature on a Cisco router permits the forwarding of traffic for which there is no specific route?
B. the switch virtual interface
Which interface allows remote management of a Layer 2 switch? A. the AUX interface B. the switch virtual interface C. the console port interface D. the first Ethernet port interface
destination IP address
Which logical address is used for delivery of data to a remote network?
broadcast
Which message delivery option is used when all devices need to receive the same message simultaneously?
A • CLI
Which method of interacting with an operating system involves typing commands at a command prompt? A • CLI B • GUI C • redirector D • kernel translator
IEEE
Which organization develops the 802 family of standards for wired and wireless LANs and MANs?
25
Which port number is used by SMTP?
B. Use the console port to locally access the switch from a serial or USB interface of the PC.
Which procedure is used to access a Cisco 2960 switch when performing an initial configuration in a secure environment? A. Use Telnet to remotely access the switch through the network. B. Use the console port to locally access the switch from a serial or USB interface of the PC. C. Use Secure Shell to remotely access the switch through the network. D. Use the AUX port to locally access the switch from a serial or USB interface of the PC.
TCP
Which protocol is responsible for controlling the size and rate of the HTTP messages exchanged between server and client?
TCP
Which protocol is used by FTP to transfer files over the Internet?
SMTP
Which protocol is used by e-mail servers to communicate with each other?
HTTP
Which protocol is used to access this website?
1 - perform the POST and load the bootstrap program 2 - locate and load the Cisco IOS software 3 - locate and load the startup configuration file or enter setup mode Refer to curriculum topic: 6.3.2 When a router is powered on, it undergoes a POST to verify that the hardware is functional, after which it proceeds by locating and loading the Cisco IOS software and then loading the startup configuration file if one is present.
Which router bootup sequence is correct?
A configured and activated router interface must be connected to another device in order to operate.
Which statement about router interfaces is true?
Segments are sent from the transport layer to the internet layer.
Which statement accurately describes a TCP/IP encapsulation process when a PC is sending data to the network?
It does not allow spaces.
Which statement describes a feature of an IOS host name configuration?
They define how messages are exchanged between the source and the destination.
Which statement is correct about network protocols?
A • requires no authentication
Which statement is true about open authentication when it is enabled on an access point? A • requires no authentication B • uses a 64-bit encryption algorithm C • requires the use of an authentication server D • requires a mutually agreed upon password
A • Only external traffic that is destined for specific internal ports is permitted. All other traffic is denied.
Which statement is true about port forwarding within a Linksys integrated router? A • Only external traffic that is destined for specific internal ports is permitted. All other traffic is denied. B • Only external traffic that is destined for specific internal ports is denied. All other traffic is permitted. C • Only internal traffic that is destined for specific external ports is permitted. All other traffic is denied. D • Only internal traffic that is destined for specific external ports is denied. All other traffic is permitted.
The TCP/IP transport layer and OSI Layer 4 provide similar services and functions.
Which statement is true about the TCP/IP and OSI models?
B. It affects the operation of the device immediately when modified.
Which statement is true about the running configuration file in a Cisco IOS device? A. It is automatically saved when the router reboots. B. It affects the operation of the device immediately when modified. C. It should be deleted using the erase running-config command. D. It is stored in NVRAM.
A • created by connecting wireless clients in a peer-to-peer network
Which statement is true concerning an ad-hoc wireless network? A • created by connecting wireless clients in a peer-to-peer network B • created by connecting wireless clients to a single, centralized AP C • created by connecting multiple wireless basic service sets through a distribution system D • created by connecting wireless clients to a wired network using an ISR
connects two networks with a wireless link
Which statement is true concerning wireless bridges?
A • connects two networks with a wireless link
Which statement is true concerning wireless bridges? A • connects two networks with a wireless link B • stationary device that connects to a wireless LAN C • allows wireless clients to connect to a wired network D • increases the strength of a wireless signal
C • Only after a virus is known can an anti-virus update be created for it.
Which statement is true regarding anti-virus software? A • Only e-mail programs need to be protected. B • Only hard drives can be protected. C • Only after a virus is known can an anti-virus update be created for it. D • Only computers with a direct Internet connection need it.
B • routing table
Which table does a router use to make decisions on where a data packet is to be sent? A • ARP table B • routing table C • network table D • forwarding table
B • encapsulation
Which term is used to describe the process of placing one message format into another format so that the message can be delivered across the appropriate medium? A• flow control B • encapsulation C • encoding D • multicasting E • access method
login line console 0 password cisco
Which three commands are used to set up a password for a person who attaches a cable to a new router so that an initial configuration can be performed? (Choose three.)
C • IP address D • subnet mask E • default gateway
Which three pieces of information must be specified on a computer to allow that computer to send and receive information across networks? (Choose three.) A • closest server B • operating system C • IP address D • subnet mask E • default gateway F • network card driver
route print netstat -r
Which two commands can be used on a Windows host to display the routing table? (Choose two.)
A. The contents of flash may be overwritten. C. Flash provides nonvolatile storage.
Which two features are characteristics of flash memory? (Choose two.) A. The contents of flash may be overwritten. B. Flash receives a copy of the IOS from RAM when a device is powered on. C. Flash provides nonvolatile storage. D. The contents of flash may be lost during a power cycle. E. Flash is a component in Cisco switches but not in Cisco routers.
Socket
1) A software structure that operates within a network device as a destination point for communications. 2) In AppleTalk networks, an entity at a specific location within a node; AppleTalk sockets are conceptually similar to TCP/IP ports
C • EAP E • pre-shared keys
16. What are two authentication methods that an access point could use? (Choose two.) A • WEP B • WPA C • EAP D • ASCII E • pre-shared keys
startup configuration IOS image Refer to curriculum topic: 6.3.2 A router loads the IOS image file and startup configuration file into RAM when it boots. Then the startup configuration file is copied into RAM as the running configuration file. The power-on self-test (POST) is a process that occurs on almost every computer during bootup. A bootstrap program is a program that is executed just after the POST.
Which two files are loaded into RAM by the router when it boots? (Choose two.)
IOS image file Startup configuration
Which two files, if found, are copied into RAM as a router with the default configuration register setting boots up? (Choose two.)
WAN interfaces LAN interfaces
Which two interfaces will allow access via the VTY lines to configure the router? (Choose two.)
Bridge Protocol Data Units (BPDUs)
A Spanning-Tree Protocol initializing packet that is sent at definable intervals for the purpose of exchanging information among bridges in networks; still received on a blocked port, but no forwarding of frames and [TERM] is allowed; are used to send configuration messages using multicast frames
DNS
A network client in a corporate environment reboots. Which type of server would most likely be used first?
Exterior Gateway Protocol (EGP)
Connects multiple Autonomous System Numbers; Can carry more routing tables than IGPs (Example: BGP)
Device one connects to device two, device two connects to device three, and so on to the last device, which connects back to the first device. Ring topologies can be implemented with a single ring or a dual ring.
Describe a ring topology.
Physical: star Logical: ring
Describe the physical and logical topologies of Token Ring media.
?
Gives you a help screen
Subnet Mask
Helps identify network and host portion of network; Default subnet masks: Class A: 255.0.0.0 or /8, Class B: 255.255.0.0 or /16, Class C: 255.255.255.0 or /24; Typically called classful address
A • naming scheme B • IP addressing scheme
Which two items are included in a network logical map? (Choose two.) A • naming scheme B • IP addressing scheme C • length of cable runs D • physical location of networking devices E • specific layout of interconnections between networking devices and hosts
C • computer name D • IP address
Which two items must be unique to each computer and cannot be duplicated on a network? (Choose two.) A • partition B • file system C • computer name D • IP address E • operating system
response time out flow control
Which two message timing mechanisms are used in data communications? (Choose two.)
B • hub C • switch
Which two networking devices are used to connect hosts to the access layer? (Choose two.) A • router B • hub C • switch D • server E • computer
A • tells a wireless device to which WLAN it belongs D • all wireless devices on the same WLAN must have the same SSID
Which two statements about a service set identifier (SSID) are true? (Choose two.) A • tells a wireless device to which WLAN it belongs B • consists of a 32-character string and is not case sensitive C • responsible for determining the signal strength D • all wireless devices on the same WLAN must have the same SSID E • used to encrypt data sent across the wireless network
B • When anti-spam software is loaded, legitimate e-mail may be classified as spam by mistake. D • Even with anti-spam software installed, users should be careful when opening e-mail attachments.
Which two statements are true concerning anti-spam software? (Choose two.) A • Anti-spam software can be loaded on either the end-user PC or the ISP server, but not both. B • When anti-spam software is loaded, legitimate e-mail may be classified as spam by mistake. C • Installing anti-spam software should be a low priority on the network. D • Even with anti-spam software installed, users should be careful when opening e-mail attachments. E • Virus warning e-mails that are not identified as spam via anti-spam software should be forwarded to other users immediately.
C • With SSID broadcast disabled, an attacker must know the SSID to connect. D • Using the default IP address on an access point makes hacking easier.
Which two statements characterize wireless network security? (Choose two.) A • Wireless networks offer the same security features as wired networks. B • Wardriving enhances security of wireless networks. C • With SSID broadcast disabled, an attacker must know the SSID to connect. D • Using the default IP address on an access point makes hacking easier. E • An attacker needs physical access to at least one network device to launch an attack.
Specifies a single host address
Host
Trace
IP command used to trace the path a packet takes through an internetwork
Presentation
Layer responsible for data encryption, compression, and translation services.
C • provides consistent interconnections across networks E • simplifies new product development
Which two statements concerning networking standards are true? (Choose two.) A • adds complexity to networks B • encourages vendors to create proprietary protocols C • provides consistent interconnections across networks D • ensures that communications work best in a single-vendor environment E • simplifies new product development
C • MAC addresses only
Which type of address is used in an Ethernet frame header? A • logical addresses only B • IP addresses only C • MAC addresses only D • broadcast addresses only
Maintenance
Which type of installation threat involves keeping spares on hand to mitigate the threat?
Integrated Services Digital Network (ISDN)
Offered as a service by telephone companies, a communication protocol that allows telephone networks to carry data, voice, and other digital traffic
Leased Lines
Permanent connections between two points leased from the telephone companies
Time-to-Live Refer to curriculum topic: 6.1.3 When a router receives a packet, the router will decrement the Time-to-Live (TTL) field by one. When the field reaches zero, the receiving router will discard the packet and will send an ICMP Time Exceeded message to the sender.
Which value, that is contained in an IPv4 header field, is decremented by each router that receives a packet?
cdp enable
Turns on CDP on an individual interface
Bridges and Switches
Used to segment networks, but they will not isolate broadcast or multicast packets.
Composite Metric
Used with routing protocols, such as IGRP and EIGRP, that use more than one metric to find the best path to a remote network. IGRP and EIGRP both use bandwidth and delay of the line by default. However, Maximum Transmission Unit (MTU), load, and reliability of a link can be used as well
Static VLAN
VLANs that are manually configured port-by-port. This is the method typically used in production networks
instant messaging
What client software enables logged in users to communicate with other logged in users in real time?
physical, data link, network, transport, session, presentation, application
What is the correct order of the layers of the OSI reference model, starting at the lowest layer and working up the model?
WAN's typically use a partial mesh topology in order to reduce the cost of connecting components and locations.
What type of mesh topology does a WAN use, and why?
IEEE
Which standards organization developed the 802.3 (Ethernet) standard?
Applies an IP access list to an interface
ip access-group
C • Trojan horse
While surfing the Internet, a user notices a box claiming a prize has been won. The user opens the box unaware that a program is being installed. An intruder now accesses the computer and retrieves personal information. What type of attack occurred? A • worm B • virus C • Trojan horse D • denial of service
Ping
A Unix-based Internet diagnostic tool, consisting of a message sent to test the accessibility of a particular device on the IP network. The acronym (from which the "full name" was formed) reflects the underlying metaphor of submarine sonar. Just as the sonar operator sends out a signal and waits to hear it echo back from a submerged object, the network user can [TERM] another node on the network and wait to see if it responds
Logical
A __________ topology describes how devices communicate with each other.
Bus
A __________ topology uses a single cable to connect all devices together.
loop-back
A address is defined as a reserved address that routes packets back to the host.
Ethernet
A baseband LAN specification created by the Xerox Corporation and then improved through joint efforts of Xerox, Digital Equipment Corporation, and Intel; similar to the IEEE 802.3 series standard and, using CSMA/CD, operates over various types of cables at 10Mbps
Link Accessed Procedure, Balanced (LAPB)
A bit-oriented Data-Link layer protocol that is part of the X.25 stack and has its origin in SDLC
Access
A brute-force password attack would be classified as what kind of attack?
1) remove Ethernet header and trailer 2) remove IP header 3) remove TCP header 4) pass data to the application
A client has decoded a frame and started the de-encapsulation process. In which order does the de-encapsulation process occur?
The packet will be sent directly to the destination host.
A computer has to send a packet to a destination host in the same LAN. How will the packet be sent?
Multicast
A computer in a given network is communicating with a specific group of computers. What type of communication is this?
OSI (Open Systems Interconnection) model
A conceptual model defined by the International Organization for Standardization (ISO), describing how any combination of devices can be connected For the purpose of communication. This model divides the task into seven functional layers, forming a hierarchy with the applications at the top and the physical medium at the bottom, and it defines the functions each layer must provide.
Transmission Control Protocol (TCP)
A connection-oriented protocol that is defined at the Transport layer of the OSI reference model. Provides reliable delivery of data connection oriented; Reliable; Protocol number 6
substitution
A customer called the cable company to report that the Internet connection is unstable. After trying several configuration changes, the technician decided to send the customer a new cable modem to try. What troubleshooting technique does this represent?
Bridges
A device for connecting two segments of a network and transmitting packets between them. Both segments must use identical protocols to communicate; function at the Data Link layer, Layer 2 of the OSI reference model. Its purpose is to filter, send, or flood any incoming frame, based on the MAC address of that particular frame; considered software based, switches are hardware based
removes the Ethernet header and trailer
A device receives an Ethernet frame and recognizes the MAC address as its own. What does the device do to the message to get to the encapsulated data?
Terminal Equipment 1
A device with a four-wire, twisted-pair digital interface; Most modern ISDN devices are of this type
Channel Service Unit/Data Service Unit (CSU/DSU)
A digital mechanism that connects end-user equipment to the local digital telephone loop
SYN flooding
A flood of packets with invalid source-IP addresses requests a connection on the network. The server busily tries to respond, resulting in valid requests being ignored. What type of attack occurred?
D • SYN flooding
A flood of packets with invalid source-IP addresses requests a connection on the network. The server busily tries to respond, resulting in valid requests being ignored. What type of attack occurred? A • Trojan horse B • brute force C • ping of death D • SYN flooding
Cut-Through Frame Switching
A frame-switching technique that flows data through a switch so that the leading edge exits the switch at the output port before the packet finishes entering the input port. Frames will be read, processed, and forwarded by devices that use this type of switching as soon as the destination address of the frame is confirmed and the outgoing port is identified
Virtual LAN (VLAN)
A group of devices on one or more logically segmented LANs (configured by use of management software), enabling devices to communicate as if attached to the same physical medium, when they are actually located on numerous different LAN segments; based on logical instead of physical connections and thus are tremendously flexible
Broadcast Domain
A group of devices receiving broadcast frames initiating from any device within the group; generally surrounded by routers because they do not forward broadcast frames
Autonomous System (AS) number
A group of networks under mutual administration that share the same routing methodology; subdivided by areas and must be assigned an individual 16-bit number by the IANA; 16-bit numbering system; Group of devices under a single technical administration; Usually an IGP is considered an AS; Ranges from 1 through 65535
Terminal Adapter (TA)
A hardware interface between a computer without a native ISDN interface and an ISDN line. In effect, a device to connect a standard async interface to a non-native ISDN device, emulating a modem
Access Link
A link used with switches and is only part of one Virtual LAN (VLAN). Trunk links carry information from multiple VLANs
Open Shortest Path First (OSPF)
A link-state, hierarchical IGP routing algorithm derived from an earlier version of the IS-IS protocol, whose features include multipath routing, load balancing, and least-cost routing; suggested successor to RIP in the Internet environment; Open standard; SPF (shortest path first) algorithm; Hello used for neighbor relationship (Hello timer = 10 secs, Hold timer = 40 seconds); Works based on area hierarchy, minimizes LSA flooding; Supports clear-text and MD5 authentication; its states include: init, two way, exstart, exchange, loading, full state; supports VLSM and CIDR; manual summarization on the boundary/border routes such as ABR and ASBR; routing update is sent using multicast address 224.0.0.5 (or 224.0.0.6 when DR/BDR present); supports special area types such as stub, totally stub and NSSA
Network Control Protocol (NCP)
A method of establishing and configuring different Network layer protocols. PPP is designed to allow the simultaneous use of multiple Network layer protocols
Classless Interdomain Routing (CIDR)
A method supported by classless routing protocols, such as OSPF and BGP4, based on the concept of ignoring the IP class of address, permitting route aggregation and VLSM that enable routers to combine routes in order to minimize the routing information that needs to be conveyed by the primary routers. It allows a group of IP networks to appear to other networks as a unified, larger entity. In CIDR, IP addresses and their subnet masks are written as four dotted octets, followed by a forward slash and the numbering of masking bits; Beyond the classful behavior; Class A address can be treated as Class B & C or vice versa; Ex: 10.0.0.0/24 [/24 is prefix-length from Class C]
Flow Control
A methodology used to ensure that receiving units are not overwhelmed with data from sending devices. Pacing, as it is called in IBM networks, means that when buffers at a receiving unit are full, a message is transmitted to the sending unit to temporarily halt transmissions until all the data in the receiving buffer has been processed and the buffer is again ready for action
Frame Relay
A more efficient replacement of the X.25 protocol (an unrelated packet relay technology that guarantees data delivery); an industry-standard, shared-access, best-effort, switched Data-Link layer encapsulation that services multiple virtual circuits and protocols between connected mechanisms
Type the command and then press the ? key.
A network administrator has forgotten the argument of an IOS command. How would the administrator get help from the IOS CLI to complete the command correctly?
C. What features are required for the devices? E. Do the routers and switches have enough RAM and flash memory for the proposed IOS versions?
A network administrator is planning an IOS upgrade on several of the head office routers and switches. Which three questions must be answered before continuing with the IOS selection and upgrade? (Choose three.) A. Are the devices on the same LAN? B. What models of routers and switches require upgrades? C. What features are required for the devices? D. Do the devices have enough NVRAM to store the IOS image? E. Do the routers and switches have enough RAM and flash memory for the proposed IOS versions? F. What ports are installed on the routers and switches?B. What models of routers and switches require upgrades?
B. SSH
A network administrator needs to keep the user ID, password, and session contents private when establishing remote CLI connectivity with a switch to manage it. Which access method should be chosen? A. AUX B. SSH C. Console D. Telnet
Packet Switching
A networking technology based on the transmission of data in packets. Dividing a continuous stream of data into small units—packets—enables data from multiple devices on a network to share the same communication channel simultaneously but also requires the use of precise routing information
C. Exit privileged EXEC mode and press Enter.
A new network administrator has been asked to enter a banner message on a Cisco device. What is the fastest way a network administrator could test whether the banner is properly configured? A. Reboot the device. B. Power cycle the device. C. Exit privileged EXEC mode and press Enter. D. Enter CTRL-Z at the privileged mode prompt. E. Exit global configuration mode.
(Not all options are used.) 1 Examine Packet Header 2 Determine Destination Network 3 Examine Routing Table 4 Identify Exit Interface to Destination from route entry 5 Move packet to forwarding interface
A packet arrives at a router interface. The router goes through a series of steps to determine where the packet should be forwarded. Place the steps of the router forwarding process in the correct order.
C. user EXEC mode
A router has a valid operating system and a configuration stored in NVRAM. When the router boots up, which mode will display? A. global configuration mode B. ROM monitor mode C. user EXEC mode D. setup mode
A • the size of the building B • the number of solid interior walls in the building C • the presence of microwave ovens in several offices
A technician has been asked to provide wireless connectivity to the wired Ethernet network of a building. Which three factors affect the number of access points needed? (Choose three.) A • the size of the building B • the number of solid interior walls in the building C • the presence of microwave ovens in several offices D • the encryption method used on the wireless network E • the use of both Windows and Appletalk operating systems F • the use of shortwave or infrared on the AP
the default gateway address
A technician is manually configuring a computer with the necessary IP parameters to communicate over the corporate network. The computer already has an IP address, a subnet mask, and a DNS server. What else has to be configured for Internet access?
The ports are operational and are receiving traffic.
A technician suspects that a Linksys integrated router is the source of a network problem. While troubleshooting, the technician notices a blinking green activity LED on some of the ports. What does this indicate?
Inverse ARP
A technique by which dynamic mappings are constructed in a network, allowing a device such as a router to locate the logical network address and associate it with a permanent virtual circuit (PVC). Commonly used in Frame Relay to determine the far-end node's TCP/IP address by sending the Inverse ARP request to the local DLCI; dynamically maps the destination IP with corresponding local DLCI; only one DLCI can be mapped with a layer 3 address (each DLCI is a P2P connection to a remote router); does not fn on sub-interfaces
HTTP, TCP, IP, Ethernet
A web client is sending a request for a webpage to a web server. From the perspective of the client, what is the correct order of the protocol stack that is used to prepare the request for transmission?
EtherChannel
Aggregates redundant links into a bundle; Can provide aggregated bandwidth, avoiding congestion; Can load balance using different algorithms; Can bundle up to eight ports; All the ports should have the same speed and duplex; Provides loop-free Layer 2 network Verification - Switch# show etherchannel summary Configuring - Switch(config-if)# channel-group <group number> mode <mode>
IPv4 Supernetting
Aggregating multiple networks (could be subnets or classfull networks) into a single network advertisement; That advertisement breaks classfull boundaries; ex: 10.0.0.0 /7 is a Supernet
Command Line Interface (CLI)
Allows you to configure Cisco routers and switches with maximum flexibility
Thinnet
Also called 10Base2. Bus network that uses a thin coax cable and runs Ethernet media access up to 185 meters
Thicknet
Also called 10Base5. Bus network that uses a thick cable and runs Ethernet up to 500 meters
The segment destination port number identifies the application that should handle it.
An Internet server is running both FTP and HTTP services. How does the server know which of these applications should handle an incoming segment?
Nothing must be done. Changes to the configuration on an IOS device take effect as soon as the command is typed correctly and the Enter key has been pressed.
An administrator has just changed the IP address of an interface on an IOS device. What else must be done in order to apply those changes to the device?
Dynamic VLAN
An administrator will create an entry in a special server with the hardware addresses of all devices on the internetwork. The server will then assign dynamically used VLANs
Hierarchical Addressing
Any addressing plan employing a logical chain of commands to determine location. IP addresses are made up of a hierarchy of network numbers, subnet numbers, and host numbers to direct packets to the appropriate destination
Data Terminal Equipment
Any device located at the user end of a user-network interface serving as a destination, a source, or both; includes devices such as multiplexers, protocol translators, and computers. The connection to a data network is made through data channel equipment (DCE)
Bridges and Switches
Break up collision domains on a LAN.
Network Segmentation
Breaking up massive networks into smaller ones.
Internetworking
Broadly, anything associated with the general task of linking networks to each other. The term encompasses technologies, procedures, and products. When you connect networks to a router, you are creating one
1 Physical Layer
Cabling issues are associated with which OSI layer?
Floating Static Route
Can be configured as a backup route; Administrative distance can be increased to make a route backup; Provide redundancy between two statically defined routes; Configuration: Router(config)#iproute <destination-network> <destination subnet mask> <next-hop> <AD value>; Verification: Router# show ip route; Router# show running-config| include iproute; Router# show iproute <prefix> <mask>; Troubleshooting cmds- Router# debug ip packet; Router# default ip routing
Trunk Port
Can have two or more VLANs configured; Can carry multiple VLAN information; By default, all the VLAN traffic is allowed from this port
cdp holdtime
Changes the holdtime of CDP packets
Read Only Memory (ROM)
Chip used in computers to help boot the device. Cisco routers use a ROM chip to load the bootstrap, which runs a power-on self test, and then find and load the IOS in flash memory by default
Dynamic Trunking Protocol (DTP)
Cisco proprietary feature that allows Cisco switches to negotiate trunk dynamically; Three modes: Auto, On, Desirable; Desirable initiates the trunk, whereas Auto responds only Verification - Switch# show interface trunk; Switch# show interface <interface> switchport Configuration - Switch(config-if)# switchportmode dynamic [desirable|auto] Disabling - Switch(config-if)# switchportnonegotiate
C. Issue the reload command without saving the running configuration.
While trying to solve a network issue, a technician made multiple changes to the current router configuration file. The changes did not solve the problem and were not saved. What action can the technician take to discard the changes and work with the file in NVRAM? A. Close and reopen the terminal emulation software. B. Delete the vlan.dat file and reboot the device. C. Issue the reload command without saving the running configuration. D. Issue the copy startup-config running-config command.
B • has higher power output
Why is IEEE 802.11 wireless technology able to transmit further distances than Bluetooth technology? A • transmits at much lower frequencies B • has higher power output C • transmits at much higher frequencies D • uses better encryption methods
Hot Standby Router Protocol (HSRP)
Cisco proprietary; uses UDP port 1985 and multicast address 224.0.0.2; active and standby roles; HSRP router with highest priority is considered "active" w/ default priority = 100; MAC address: 0000.0c07.acxx (xx refers to the group number in hexadecimal); preemption disabled by default; HSRP/VRRP = No load-sharing feature; MHSRP can be used for load sharing; Requires multiple VLANs; provides high network availability and provides nearly instantaneous hardware fail-over without administrator intervention; generates a Hot Standby router group, including a lead router that lends its services to any packet being transferred to the Hot Standby address. If the lead router fails, it will be replaced by any of the other routers—the standby routers—that monitor it authentication - supported as plain text or MD5; plain-text configuration: sw1(config-if)# standby <group-id> authentication <password> Implementation: Enabling HSRP in the interface - switch(config-if)# standby <group-id> <virtual-ip>; configure priority with switch(config-if)# standby <group-id> priority <priority>; enabling preemption is switch(config-if)# standby <group-id> preempt Verification: Switch# show standby, Switch# show standby brief
OSI Model
Comprised of seven layers; hierarchy with the applications at the top and the physical medium at the bottom; the benefits of using a layered approach include: Provides easier troubleshooting, Standardizes the networking architecture, Allows vendor interoperability
TFTP
Conceptually, a stripped-down version of FTP, it's the protocol of choice if you know exactly what you want and where it's to be found. [TERM] doesn't provide the abundance of functions that FTP does. In particular, it has no directory browsing abilities; it can do nothing but send and receive files
Copies the startup-config to running-config
Config memory
BPDU Filter
Configured in access ports; Does not send or receive BPDU; Does not go into err-disabled when it receives unauthorized BPDU; Configured with the spanning-tree bpdufilter enable interface-specific command; Verified with: Switch# show spanning-tree interface <interface> detail
IOS Securing Device Access
Configuring enable password: Switch(config)# enable password <password> OR Switch(config)# enable secret <password> Configuring console password: Switch(config)# line console 0; Switch(config-line)# password <password> Configuring Telnet password: Switch(config)# line vty0 4; Switch(config-line)# password <password>; Switch(config-line)# login OR Switch(config)# username <username> privilege 15 password <password>; Switch(config-line)# login local
Local Loop
Connection from a demarcation point to the closest switching office
A. to identify the device during remote access (SSH or telnet)
Why is it important to configure a hostname on a device? A. to identify the device during remote access (SSH or telnet) B. a hostname must be configured before any other parameters C. a Cisco router or switch only begins to operate when its hostname is set D. to allow local access to the device through the console port
Link State Advertisements (LSA)
Contained inside of link-state packets (LSPs), these advertisements are usually multicast packets, containing info about neighbors and path costs, that are employed by link-state protocols. Receiving routers use LSAs to maintain their link-state databases and, ultimately, routing tables; carried within an OSPF link state update packet; different types carry different data; age out after 1 hour, refreshed every 30 mins
Unshielded Twisted Pair (UTP)
Copper wiring used in small-to-large networks to connect host devices to hubs and switches. Also used to connect switch to switch or hub to hub
Banner
Creates a banner for users who log in to the router
Access-list
Creates a list of tests to filter the networks
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Private IPv4 address
Defined in RFC 1918; For internal use only; Range of private address: Class A: 10.0.0.0 through 10.255.255.255, Class B: 172.16.0.0 through 172.31.255.255, Class C: 192.168.0.0 through 192.168.255.255
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All components are connected to and share a single wire using special types of connectors or transceivers.
Describe a bus topology.
It provides a temporary connection across a phone circuit and are typically used for backup of primary circuits and for temporary boosts of bandwidth.
Describe a circuit-switched service.
A permanent connection between two sites in which the bandwidth is dedicated to that company's use. Common when services such as voice, video, and data, must traverse the connection.
Describe a dedicated circuit.
It has a single connection between two components, and two components can directly communicate without interference from other components.
Describe a point-to-point topology.
A central device has many point-to-point connections to other components. Star topologies are used in environments where many different devices need to be connected, with a hub or switch at the center of the star.
Describe a star topology.
Cell-switched services provide the same features that dedicated circuits offer, but their advantage is that a single device can connect to multiple devices on the same interface.
Describe cell-switched services.
Every network component is connected to every other network component.
Describe full meshing.
Packet-switched services are similar to cell-switched services, except where cell-switched services switch fixed-length packets called cells, packet-switched services switch variable-length packets. This feature makes them better suited for data services.
Describe packet-switched services.
Every network component is NOT connected to every other component.
Describe partial meshing.
It describes how network components are connected together, and can be either full or partial.
Describe the mesh topology in a network environment.
Physical: bus, star, or point to point Logical: bus
Describe the physical and logical topologies of Ethernet media.
Physical: ring Logical: :ring
Describe the physical and logical topologies of FDDI media.
Sets a description on an interface
Description
IOS Monitoring Memory and Images
Display current IOS version running: Router# show version Display all memory locations and file names: Router# dirall Display saved, startup configuration file: Router# show startup-config Display current running configuration: Router# show running-config
flash Refer to curriculum topic: 6.3.2 The IOS image is typically stored in flash memory. If the image is not in flash memory when the router boots, the router bootstrap program can look for it on a TFTP server.
During the boot process, in what memory location will the router bootstrap program look for the IOS image if a TFTP server is not used?
switch the packet to the directly connected interface
During the process of forwarding traffic, what will the router do immediately after matching the destination IP address to a network on a directly connected routing table entry?
ROM Refer to curriculum topic: 6.3.1 ROM is used to store bootup instructions, basic diagnostic software, and a copy of a limited IOS. NVRAM stores the startup configuration file. RAM provides temporary storage of the running configuration file. Flash is used to store the full Cisco IOS on a device.
During troubleshooting procedures, from which location will most Cisco routers load a limited IOS?
