Midterm cnt
AS
(Autonomous System) a group of networks, often on the same domain, that are operated by the same organization.
MMF(multimode fiber)
-LED light source -Typically 100s of meters -LAN backbone links
subnet mask
A 32-bit number assigned to each host for dividing the 32-bit binary IP address into network and node portions...helps one computer find another
Resolvers
A DNS client that requests information from DNS name servers.
MAC address
A Media Access Control address is a hardware address that uniquely identifies each node on a network...Contain two parts, 48 bits long and are written as hexadecimal numbers 00:60:8C:00:54:99
PING (Packet Internet Groper)
A TCP/IP troubleshooting utility that can verify that TCP/IP is installed, bound to the NIC, configured correctly, and communicating with the network. PING uses ICMP to send echo request and echo reply messages that determine the validity of an IP address.
ifconfig
A TCP/IP utility including the MAC addresses of the NIC
netstat
A TCP/IP utility that shows the status of each active connection. includes information such as: port where TCP/IP is running which network connections are currently established for a client how many messages have been handled by a network interface since it was activated how many data errors have occured on a particular network interface
tracert
A Windows utility that uses ICMP echo requests to trace the path from one networked node to another, identifying all intermediate hops between the two nodes.
Latency
A brief delay takes place between the instant when data leaves the source and when it arrives at irs destination
media converter
A device that enables networks or segments using different media to interconnect and exchange signals.
Router
A device that manages traffic between two or more networks and can help find the best path for traffic to get from one network to another.
demarc (demarcation point)
A device that marks the dividing line of responsibility for the functioning of a network between internal users and upstream service providers.
optical power meter (OPM)
A device that measures the amount of light power transmitted on a fiber-optic line. Also called laser power meter or light meter.
Continuity Tester
A device used to test whether or not cable is carrying a signal to its destination or not
What is a rack diagram?
A diagram that shows how to setup a rack.
IDF (intermediate distribution frame)
A distribution frame that provides an intermediate connection between the MDF and end-user equipment. (Racks holding the network equipment or room that houses both racks and equipment)
EMI(ElectroMagnetic interference)
A disturbance that affects an electrical circuit due to electromagnetic induction
Remote Desktop Services
A feature of Windows Server 2008 and later editions of Windows Server that allows technicians to manage remote applications.
Multiplexing
A form of transmission that allows multiple signals to travel simultaneously over one medium.
L3 Switch
A switch that is capable of interpreting layer 3 data and works much like a router. it supports the same routing protocols and makes routing decisions.
Half Duplex
A type of transmission in which signals may travel in both directions over a medium, but in only one direction at a time.
SSID (Service Set Identifier)
A unique character string used to identify an access point on an 802.11 network.
nslookup
A utility that is used to test and troubleshoot domain name servers. Useful for verifying that a host is configured correctly or for troubleshooting DNS resolution problems
Port Address Translation (PAT)
A variation of network address translation (NAT) that assigns a different TCP port number to each packet.
TLS (Transport Layer Security)
A version of SSL standardized by the IETF (Internet Engineering Task Force). TLS uses slightly different encryption algorithms than SSL, but otherwise is very similar to the most recent version of SSL.
Cable Certifier
A very powerful cable testing device used by professional installers to test the electrical characteristics of a cable and then generate a certification report, proving that cable runs pass TIA/EIA standards.
Scanning
A wireless node that is on and running that is periodically surveying its surroundings for evidence of an access point
LWAPP (Lightweight Access Point Protocol)
A wireless protocol created by Cisco that makes centralized wireless management possible. LWAPP directs all wireless frames to the wireless controller by adding extra headers to the frames, but it is also considered a lightweight protocol because the headers are relatively small.
link-local address
An IP address that is automatically assigned by an operating system to allow a node to communicate over its local subnet if a routable IP address is not available. ICANN has established the range of 169.254.0.0 through 169.254.254.255 as potential link-local IPv4 addresses. IPv6 link-local addresses begin with the prefix FE80::/10.
two-post rack
An equipment rack consisting of two vertical side posts to which equipment is attached via brackets incorporated in the posts.
global address
Any address that appears on the outside portion of the network.
Fading
As a signal runs into various obstacles its energy will gradually fade which causes the strength of the signal thay reaches the receiver to be lower that the transmitted signals strength
site survey
Assesses client requirements, facility characteristics, and coverage areas to determine an access point arrangement that will ensure reliable wireless connectivity within a given area.
Class A
Assigned to Government, 1 to 126 , 16 million possible IP addresses in each network, default subnet mask 255.0.0.0
Class D
Assigned to Multicasting 224 to 239
Protect Cables
Avoid laying cables across the floor where it might sustain damage from rolling chairs or foot traffic
socket
Both a host's IP address and a process's TCP or UDP port. (TCP 23) If a host has an IP address of 10.43.3.87...10.43.3.87
Full Duplex
Communication that happens in two directions at the same time.
Signals
Copper cable carries electrical signals or pulses of electricity(pulse for 1 and no pulse for 0. Fiber cable carries light signals or pulses of light(pulse for 1 and nonpulse for 0.
client-server applications
Data or a service requested by one computer from another.
PD
Device like an IP phone that is powered from switch
dual-stacked
Devices that support both IPV6 and IPV4. Necessary on routers tunneling IPv6 across IPv4 and to support NAT proxying.
TDM(Time Division Multiplexing)
Divides a channel into multiple intervals of time(slots). Time slots are reserved for their designated nodes regardless of whether the node has data to transmit. this can be inefficient if some nodes on the network rarely send data
SOW (statement of work)
Documents in detail the work that must be completed for a particular project.
FTP
File Transfer Protocol- file transfer- control
What is a routing metric? Examples?
Finding the best route or best path for messages to take across networks. Examples - Hop count, Theoretical bandwidth and actual throughput, delay, or latency.
MU-MIMO (multiuser MIMO)
In the context of 802.11ac wireless networking, the ability for access points to use multiple antennas in order to issue multiple signals to different stations at the same time, thereby reducing congestion and contributing to faster data transmission. MU-MIMO will become available with Wave 2 802.11ac products.
frame aggregation
In the context of 802.11n and 802.11ac wireless networking, a technique for combining multiple data frames into one larger frame called an A-MSDU (Aggregated Mac Service Data Unit) or A-MPDU (Aggregated Mac Protocol Data Unit). Both approaches combine multiple frames to reduce overhead. 802.11ac actually uses A-MPDU for all transmissions by default.
MIMO (multiple input-multiple output)
In the context of 802.11n wireless networking, the ability for access points to issue multiple signals to stations, thereby multiplying the signal's strength and increasing their range and data-carrying capacity. Because the signals follow multipath propagation, they must be phase-adjusted when they reach their destination.
Verifying IP Addresses on a Windows Computer
Ipconfig
installation
New software, such as CRM(customer relationship management) software for sales rep or a financial software package for accountants, must be installed on the relevant devices and incorporated with network resources
Nmap
Nmap was originally designed for Linux as a command-line utility, but has since been expanded for compatibility on several other oses. It's now available in GUI form called Zenmap.
Dynamic Ports
Number assigned by a client or server as the need arises. ex. If a client program has several open sockets with multiple servers, it can use a different dynamic port number for each socket
Port #
Number assigned to a process such as an application or service that can receive data. (Used to find a process running on a computer)
OSI Model
Open Systems Interconnection Model
MAC address format- What is the OUI
Organizationally Unique Identifier, which identifies the NIC's manufacturer...First 24 bits
SNMP (Simple Network Management Protocol)
Programs that monitor and gather information about network traffic and can alert network administrators about adverse conditions that need attention
ifconfig up
Reinitializes the interface after it has been taken down(via the ifconfig down command), so that it is once again available to the network
RFP (Request for Proposal)
Request to vendors to submit a proposal for a product or service your company wants to purchase.
RJ45
STP and UTP use these modular connectors and data jacks which look similar to analog telephone connectors and jacks. (RJ11 are used as telephone connection standard)
Small Form Factor Pluggable (SFP)
Same function as GBICs but is more compact allowing more ports per inch
SSH
Secure Shell- Secure communications between computers
SMB
Server Message Block- Network File Sharing...file sharing on a network
DNS server
Servers that are responsible for tracking computer names and their IP addresses
NOS (network operating system)
They control access to the entire network, how users and programs access resources on the network. Some examples are windows, Ubuntu, and red hat enterprise Linux.
Work Area
This area encompasses workstations, printers, and other network devices, and all the patch cables, wall jacks , and horizontal cabling necessary to connect these devices to a data room
cable trays - use cable trays and other cable management devices - why?
To keep your cables well managed and organized.
Telnet
Unencrypted control of remote computers
Significance of 255.255.255.255
Used for broadcast messages by TCP/IP background processes. A broadcast message is read by every node on the network
Firewall
a dedicated device or software on a computer that selectively filters or blocks traffic between networks.
mux(multiplexer) & demux(demultiplexer)
a device that can combine many signals on a channel (mux) is required at the transmitting end of the channel. at the receiving end a (demux) separates the combined signals
NFC(Near Field Communication)
a form of RFID and transfers data wirelessly over very short distances. used by smartphones amd other devices to easily transmit data
recursive query
a query that demands a resolution or the answer "It can't be found"
iterative query
a query that does not demand resolution.
Wireless Bridges
access points used to extemd wired access to remote areas of the network
on-boarding
an application that allows users access to shared resources within a network
FTP(File Transfer Protocol)
an internet standard that permits file uploading and downloading to and from other computers on the internet
Forwarding DNS server
an optional server that receives queries from local clients but does not work to resolve the queries. Typically, a forwarding server will maintain its own DNS cache from previous queries, and so it might already have the information the client needs. If not it forwards the query to another server to resolve.
wall jack
an outlet for voice and data connectors-cables that connect a workstation to a data room
refraction
as a wave traveks into and through a different transmission medium, such as when traveling through glass or other solids, the wave's direction, speed, and wavelength are altered or refracted.
What is IP? Function/purpose?
belongs to the network layer of the OSI model. It specifies where data should be delivered, identifying the data's source and destination IP addresses.
noise
degraded or distortion of a signal on a network, measured in db. noise is caused by(two common sources are) EMI & Crosstalk
Topology
describes how the parts of a whole work together
What are some programs/applications that can be used for creating network diagrams?
draw.io, MS Visio
MLA(master license agreement)
grants a license from a creator, developer, or producer, such as a software producer, to a third party for the purposes of marketing, sublicensing, or distributing the product to consumers as stand-alone product or as part of another product
BSS(Basic Service Set)
group of nodes that share an access point BSSID- the identifier for this group
name servers
hold databases, which are organized in a hierarchical structure.
CNAME (Canonical name) record
holds alternative names for a host. These names can be used in place of the canomical name, which is the complete and properly formatted name, such as www.mycompany.com
Authentication
is the process of comparing and matching a client's credentials with the credentials in a client database to enable the client to log on to the network. The authentication process can be somewhat strengthened by using MAC Filtering.
What is Bluetooth?
it unites mobile devices, PCs, and accessories under a single communications standard. Bluetooth operates in the radio band of 2.4 GHz to 2.4835 GHz and hops between frequencies in that band. Most times it needs to be in close proximity.
what is a Core or Interior router?
located inside networks within the same autonomous system.
What are some items that should be recorded in documentation?
logical and physical connections, inventory, IP Address utilization, vendors (such as contact information, warranty information, service agreements, and troubleshooting instructions); and internal operating procedures, policies and standards.
Significance of 127.0.0.1
loopback address. used for research or can indicate your own computer
unicast address
the IP address of a single host on a network
namespace
the entire collection of computer names and their associated IP addresses stored in databases on DNS name servers around the globe.
What is RFID
uses electromagnetic fields to store data on a small chip in an RFID tag, which includes an antenna that can both transmit and receive, and possibly a battery
ping -6
verifies connectivity on IPv6 networks
tcpdump
A command-line protocol analyzer. Administrators use it to capture packets.
Ring Topology
A LAN configuration in which all nodes are connected in a closed loop...seldomly used today
What is a routing table?
A database that holds information about where the hosts are located and the most efficient way to reach them.
Email Service
A client server application that involves two servers.
anycast address
A method of communications where a set of packets are sent to the first or closest computer within a set of computers.
TCP/IP (Transmission Control Protocol/Internet Protocol)
A collection of Internet communication protocols between two computers. The TCP protocol is responsible for an error free connection between two computers, while the IP protocol is responsible for the data packets sent over the network.
LAN (Local Area Network)
A network of computers and other devices that is confined to a relatively small space, such as one building or even one office.
Client-server Network Model
A network where resources are managed by the NOS via a centralized directory database.
patch cable
A relatively short section (usually between 3 and 25 feet) of cabling with connectors on both ends. Used to connect two electronic devices together.
Multilayer Switch
Like a router, a multilayer switch can make traffic forwarding decisions based on Layer 3 information. Although multilayer switches more closely approach wire-speed throughput that most routers, routers tend to have a greater feature set and are capable of supporting more interface types than a multilayer switch.
NTP
Network Time Protocol- Network Time Synchronization...synchronize clocks on computers throughout a network
STP (shielded twisted pair)
A type of copper-based cable containing twisted-pair wires that are not only individually insulated, but are also surrounded by a shielding made of a metallic substance such as foil.
What are the classes of IPv4 Addresses?
A, B, C, D, E
entrance facility
The location where an incoming network service (whether phone, Internet, or long-distance service) enters a building and connects with the building's backbone cabling. (Contains service provider's equipment)
What is a broadcast Domain?
The network area in which all hosts receive broadcasts
Rollback
The process of reverting to a previous version of a software application after attempting to patch or upgrade it.
RDP (Remote Desktop Protocol)
The protocol used by Microsoft's Terminal Services implementations to provide secure, encrypted transmissions that allow a technician to remote in
What is a radiation pattern? Recognize what it looks like.
The relative strength over a three-dimensional area of all the electromagnetic energy an antenna sends or receives.
Z-Wave
a smart home protocol that provides two basic types of functions: signaling, to manage wireless connections, and control, to transmit data and commands between devices.
probe
a special frame that is transmitted on all available channels within the computers frequency range
Skimming
a type of fraud where the culprit installs a card reader on a gas station pump or ATM. The criminal then returns later to collect the device and retrieve the stolen data.
Baseband
a type of transmission in which the entire channel capacity of the communications medium (such as cable) is used by one data signal, enabling only one node to transmit at a time
rogue access point
an unauthorized access point to a wireless network
UTP (Unshielded Twisted Pair)
cable is a type of copper-based cable that consists of one or more insulated twisted-pair wires encased in a plastic sheath.
L4 Switch
capable of interpreting Layer 4 data. They operate anywhere between Layer 4 and Layer 7 and are also known as content switches or application switches. Among other things, the ability to interpret higher layer data enables switches to perform advanced filtering, keep statistics, and provide security functions.
RFI(Radio Frequency Interference)
electromagnetic interference caused by radio waves
Interference
electromagnetic waves in the atmosphere can interfere with wireless communications similar to how EMI(Electro magnetic interference) affects wired transmissions.
KVM (Keyboard, Video, and Mouse) switch
connects to a single console to provide a central control portal for all devices on the rack
Bluesnarfing
a connection is used to download data without permission
Bluejacking
a connection is used to send unsolicited data
Global Unicast
2000::/3
What is PSE?
Switch that is PoE capable
ARP
(Address Resolution Protocol) works in conjunction with IPv4 to discover the MAC address of a node on the local network and to maintain a database that maps local IP addresses to MAC addresses
MAN(Metropolitan Area Network)
A large computer network usually spanning a city
IPv4 address
Internet Protocol version 4 (IPv4) address is a unique 32-bit number represented in dotted decimal notation that identifies individual nodes on a network... ex. 72.56.105.12
What is IoT?
Internet of Things (IoT) is made up of any device that can be connected to the internet that is, any sensor, computer, or wearable device that talks to other devices over a network.
Bus Topology
Network configuration wherein all computers connect to the network via a central cable...not used anymore
data frames
Network traffic that is broadcasted to all connected devices by a hub. responsible for csrrying data between nodes
remote wipe
clears a device of all important information, permissions, and apps without having physical access to the device
wireless spectrum
commonly called the airwaves, is the frequency range of electromagnetic waves used for data and voice communication.
What is connection-less protocol?
communication between two network end points in which a message can be sent from one end point to another without prior arrangement.
Coax Cable
construction-central metal core surrounded by an insulator, a braided metal shielding, and an outer cover called the sheath or metal jacket. The core can have a solid metal wire or several thin strands of metal wire and carries the electromagnetic signal. The shielding protects the signal against noise and is a ground for the signal. The plastic insulator can be polyvinyl chloride(PVC) or teflon and protects core from the metal shield. the sheath protects cable feom physical damage and might be PVC or a more expensive fire resistant plastic
alien cross talk
cross-talk that occurs between two cables
FEXT(far end crosstalk)
crosstalk measured at the far end of the cable feom the signal source
NEXT
crosstalk that occurs between wire pairs near the source of a signal
Structured cabling standard
the best way to install networking media to maximize performance and minimize upkeep...based on hierarchical design and assumes a network is set up in a star topology
MSA(master service agreement)
A contract that defines the terms of future contracts between parties, such as payment terms or arbitration arrangements
Patch
A correction, improvement, or enhancement to part of a software application, often distributed at no charge by software vendors to fix a bug in their code or to add slightly more functionality.
war driving
A hacker searches for unprotected wireless networks by driving around with a laptop configured to receive and capture wireless data transmissions
APIPA
Automatic Private IP Addressing
Unique local unicast
FC00::/7or8
Multicast
FF00::/8
Standard for PoE
IEEE 802.3af
HTTP (Hypertext Transfer Protocol)
Primary protocol used by Web servers and browsers(clients)
off-boarding
The ability to quickly remove devices from the organization's network.
Advantages of a client-server network
•User accounts and network are assigned in one place •access to shared resources can be centrally granted to a single user or group of users. •problems on the network can be monitored, diagnosed, and often fixed from one location. •client server networks are also more scalable than peer-to-peer networks. In other words, it's easier to add computers and other devices to client-server network.
DSSS
(Direct Sequence Spread Spectrum)-data streams are divided and encoded into small chunks, called chips, which are spread over all available frequencies within one of three, wide channels, all at the same time. The process of dividing and encoding the data is called chipping, and the spreading ratio used to transform the data is called chipping code, which is unique to each device. DSSS uses the available bandwidth more efficiently than FHSS and tends to have a higher throughput.
What is EMV Chip?
(Europay, Mastercard, and visa) EMV chips perform a small, amount of processing with each transaction where a unique transaction number is generated anytime the chip is activated. This means that, even if a thief captures your payment information at the point of sale, the transaction number cant be used again.
ICMP
(Internet Control Message Protocol) a network layer, core protocol that reports on the success or failure of data delivery. It can indicate when part of a network is congested, when data fails to reach its destination, and when data has been discarded because the allotted Time to Live has expired.
What is MTU?
(Maximum Transmission Unit) the largest size, in bytes, that routers in a message's path will allow at the Network layer.
what is RIP?
(Routing Internet Protocol) A distance-vector routing protocol, is the oldest routing protocol. It has limited metrics, meaning it only considers the number of hops between nodes when determining the best path. The convergence time is poor and may take several minutes for new information to propagate to the far reaches of the network. Has limited network size.
What is TCP? Function and purpose?
(Transmission control protocol) operates in the transport layer of the OSI and provides reliable data delivery services
What is UDP? Function/purpose?
(User Datagram Protocol) an unreliable, connection-less protocol, The term unreliable does not mean that UDP can't be used reliably, Instead it means that UDP does not mean guarantee dilivery of data, and no connection is established by UDP before data is transmitted. UDP provides no handshake to establish a connection, acknowledgment of transmissions received, error checking, sequencing, or flow control and is, therefore more efficient and faster than TCP.
WPA
(Wi-Fi Protected Access) A method for encrypting data transmitted over wireless networks.
WPA2
(WiFi Protected Access 2) more permanent upgrade to WEP and uses AES technology
WEP
(Wired Equivalent Privacy) when configuring WEP, you establish a character string that is required to associate with the access point, also known as the network key.
AD
(administrator distance) each routing protocol is assigned a default AD, which is a number indicating the protocol's reliability, with lower values being given to higher priority.
What is an EGP? Use?
(exterior gateway protocols) routing protocols used by edge routers and exterior routers to distribute data outside of the autonomous systems. BGP is the one current example EGP.
What is an IGP? Use?
(interior gateway protocols) routing protocols used by core routers and edge routers within autonomous systems. IGPs are often grouped according to the algorithms they use to calculate best paths
What dies ITU control/regulate?
(international telecommunication Union) is a United Nations agency that sets standards for international telecommunications including wireless frequency allocations an satellite orbits.
Power over Ethernet (PoE)
) Technology that allows for the transmission of electrical power over Ethernet (twisted pair) cabling.
pitfalls to avoid
*wrong ssid *security type mismatch *wrong passphrase *overlapping channels or mismatched frequencies *mismatched standards *incorrect antenna placement *interference *simultaneous wired and wireless connections *problems with firmware updates *unoptimized access point power levels *incorrect antenna type *client saturation or overcapacity
What are some advantages and disadvantages of peer-to-peer network
+1. Easy to maintain +2. No dependence on server +3. Cheap -4. No centralised management. Devices need to install their updates and security individually. Backups are complicated. -5. Duplicates can be created. It is easy to lose track of the most updated copy of the file and where it is stored.
What security should be done in your cable plant?
-Every data room should be secured behind a locked door with only limited IT personnel having copies of the keys -Never leave the room unlocked -Security cameras -badge readers
SMF(Single-Mode Fiber)
-Lazer light source -up to 1000s of kilometers -used for WAN connections
The NOS is responsible for:
-Manages client data, resources -Ensures authorized user access -Controls user file access -Restricts user network access -Dictates computer communication rules -Supplies application to clients
Labeling Conventions for your network devices
-Use names that are as descriptive as possible -Only include fields that are absolutely essential in identifying the device -Don't overcomplicate the name with useless info -Think big-picture down to details -Consider security risks
Unshielded Twisted Pair (UTP)
-no additional shielding -most common twisted pair cabling -less expensive than STP
Similarities between wired and wireless networks
-originate from electrical current traveling along a conductor same layer 3 and up protocols
Well Known Ports
0-1023 Preassigned by IANA for use by common or well known services such as Telnet, FTP, and HTTP
Basic steps of DNS resolving process
1. The resolver on the client computer first searches its DNS cache, a database stored on the local computer, for the match. if it cant find the information there, the resolver sends the DNS message or query to its local DNS server. 2. the local name server queries a root server with the request. the root server responds to the local name server with a list of IP addresses of TLD name servers responsible for the .edu suffix 3. the local name server makes the same request to one of the local TLD name servers responsible for the .edu suffix. The TLD name server responds with the IP address of the mdc.edu authoritative server. 4. The local name server makes the request to the authoritative name server at Miami DADE Community College, which responds to the cengage name server with the IP address of the www.mdc.edu host. 5. the local name server responds to the cliten resolver with the requested IP address. Both the Cengage name server and the Cengage client computer store the information in their DNS caches, and therefore, don't need to ask again until that information expires.
Data Encapsulation Process
1. The upper-layer user data is converted for transmission on the network 2. The data stream is then handed down to the Transport layer, which sets up a virtual circuit to the receiving device by sending over a synch packet 3. Next, the data stream is broken up into smaller pieces, and a Transport layer header is created and attached to the header of the data field - The piece of data is called a segment (a PDU); Each segment can be sequenced so the data stream can be put back together on the receiving side exactly as it was transmitted 4. Each segment is then handed to the Network layer for network addressing and routing through the internetwork - Logical addressing (for example, IP and IPv6) is used to get each segment to the correct network; The Network layer protocol adds a control header to the segment handed down from the Transport layer, and what we have now is called a packet or datagram *The Transport and Network layers work together to rebuild a data stream on a receiving host; the Data Link layer that's responsible for taking packets from the Network layer and placing them on the network medium (cable or wireless)* 5. The Data Link layer encapsulates each packet in a frame, and the frame's header carries the hardware addresses of the source and destination hosts - If the destination device is on a remote network, then the frame is sent to a router to be routed through an internetwork; Once it gets to the destination network, a new frame is used to get the packet to the destination host - To put this frame on the network, it must first be put into a digital signal 6. Since a frame is really a logical group of 1s and 0s, the physical layer is responsible for encoding these digits into a digital signal, which is read by devices on the same local network; The receiving devices will synchronize on the digital signal and extract (decode) the 1s and 0s from the digital signal
How does CMSA/CA work?
1.) Check for transmissions 2.) If the node detects no transmission activity on the network, it waits a brief, random amount of time, and then sends its transmission. if the source does detect activity, it waits a brief period of time before checking the channel again. 3.) The destination node receives the transmission and, after verifying its accuracy, issues, an ACK (acknowledgment) packet to the source. 4.) If the source receives this acknowledgment, it assumes the transmission was properly completed. interference or other transmissions on the network could impede this exchange. If, after transmitting a message, the source node fails to receive acknowledgment from the destination node, it assumes its transmission did not arrive properly, and it begins the CSMA/CA process anew.
All routers can do what tasks?
1.) Connect dissimilar networks, such as LAN and a Wan, which use different types of routing protocol. 2.)Interpret Layer 3 and often layer 4 addressing and other information (such as quality of service indicators) 3.)Determine the best path for data to follow from point A to point B. The best pathos the most efficient route to the message's destination calculated by the router, based upon the information the router has available to it. 4.)Reroute traffic if the path of first choice is down but another path is available
What are the 3 handshakes?
1.) SYN (request for a connection) 2.)SYN/ACK (response to the request) 3)ACK (connection established)
Routers can perform what optional functions?
1.)Filter broadcast transmissions to alleviate network congestion. 2.) Acting as a simple, prevent certain types of traffic from getting to a network, enabling customized segregation and security. 3.) support simultaneous local and remote connectivity. 4.) Provide high network fault tolerance through redundant components such as power supplies or network interfaces. 5.)Monitor network traffic and report statistics. Diagnose internal or other connectivity problems and trigger alarms.
bandwidth/throughput prefixes
1000 bits per second-kilo 1000000 per second- mega 1000000000 per second-giga 1000000000000 per second-tera
Class B
128-191 128.0.x.y to 191.255.x.y big businesses 16000 approximate number of possible networks , 65000 approximate number of possible IP addresses in each newtork
What is the maximum frame size for Ethernet Layer 2 Standard?
1518 bytes maximum frame size
Class C
192-223 192.0.0.x to 223.255.255.x, 2 million approximate number of possible networks, 254 approximate number of possible IP addresses in each network Assigned to all else
Multimode Fiber cable sizes
50/125um or 62.5/125um
What is the minimum frame size for Ethernet Layer 2 Standard?
64 bytes minimum frame size
singlemode fiber cable sizes
8/125um or 10/125um
WLAN standards specs
802.11b- 2.4 GHz, 11 Mbps, 100m 802.11a- 5 GHz, 54 Mbps, 50m 802.11g- 2.4 GHz, 54 Mbps, 100m 802.11n- 2.4 GHz, 600 Mbps, indoor-70m; outdoor-250m 802.11ac- (wave 1)3 data streams- 5 GHz, 1.3 Gbps, Indoor: 70m, Outdoor: 250m (wave 2)4 data streams- 5 GHz, 3.47 Gbps, Indoor: 70m, Outdoor: 250m (wave 3)8 data streams- 5 GHz, 6.93 Gbps, Indoor: 70m, Outdoor: 250m
backbone
A central conduit that connects the segments of a network and is sometimes referred to as "a network of networks"
wireless controller
A central management console for all of the APs on a network. Either for initial use to configure APs or APs remain connected.
IP (Internet Protocol)
A connectionless Network-layer protocol that is responsible for sending data packets across a network.
fiber optic cable
A form of cable that contains one or several glass or plastic fibers in its core. Data is transmitted via pulsing light sent from a laser or light-emitting diode (LED) through the central fiber (or fibers).
network diagram
A graphical representation of a network's devices and connections.
What is a wiring schematic?
A graphical representation of a network's wired infrastructure.
WAN(Wide Area Network)
A group of LANs that spread over a wide geographical area
ESS(Extended Service Set)
A group of access points connected to the same LAN. -BSSes that belong to the same ESS share a special identofoer called an ESSID
Network
A group of computers and other devices connected by some type of transmission media
Web service
A self-contained business application that operates over the Internet.
SLA (Service Level Agreement)
A legally binding contract or part of a contract that defines, in plain language and in measurable terms, the aspects of a service provided to a customer. Specific details might include contract duration, guaranteed uptime, problem management, performance benchmarks, and termination options.
IS-IS (Intermediate System to Intermediate System)
A link-state routing protocol that uses a best-path algorithm similar to OSPF's. IS-IS was originally codified by ISO, which referred to routers as "intermediate systems," thus the protocol's name. Unlike OSPF, IS-IS is designed for use on interior routers only. Easy to adapt to IPv6. More scalable than OSPF but OSPF is more common
Domain
A logical group within a server that controls network access
heat map
A map that measures Wi-Fi signals and other electromagnetic noise in a specific location.
Multicasting
A means of transmission in which one device sends data to a specific group of devices (not necessarily the entire network segment) in a point-to-multipoint fashion.
What is static routing? Use?
A network administrator configures a routing table to direct messages along specific paths between networks. For example, its common to see a static route between a small business and its ISP. However static routing can't account for occasional network congestion, failed connections, or device moves and they require human intervention.
ICANN (Internet Corporation for Assigning Names and Numbers)
A nonprofit organization charged with setting many policies that guide how the internet works
Patch Panel
A panel of data receptors which can be mounted to a wall or a rack and provides a central termination point when many patch cables converge in a single location
Subnet
A part of a network in which all nodes shares a network addressing component and a fixed amount of bandwidth.
static IP address
A permanent IP address that is manually assigned to a computer. This can be used to set up a home file server, add a second router to a network, or enabling access to a computer when away from home/work.
CAPWAP (Control and Provisioning of Wireless Access Points)
A proprietary protocol created by Cisco to replace LWAPP. Both LWAPP and CAPWAP make centralized wireless management possible, and both direct all wireless frames to the wireless controller by adding extra headers to the frames.
SFTP (Secure File Transfer Protocol)
A protocol available with the proprietary version of SSH that copies files between hosts securely. Like FTP, SFTP first establishes a connection with a host and then allows a remote user to browse directories, list files, and copy files. Unlike FTP, SFTP encrypts data before transmitting it.
POP3 (Post Office Protocol version 3)
A protocol used from retrieving email from a mailbox on the mail server.
what is dynamic routing? use?
A router automatically calculates the best path between two networks and accumulates this information in the routing table. If congestion or failures affect the network, a router using dynamic routing can detect the problems and reroute messages through a different path. When a router is added to a network, dynamic routing ensures that new router's routing tables are updated.
What is a routing table used for?
A router relies on its routing table to identify which network a host belongs to and which of the router's interfaces points toward the best next hop to reach that network.
What is overhead?
A routing protocol is rated on its overhead, or the burden placed on the underlying networks to support the protocol.
WPA attack
A security exploit in which a hacker uses a program to intercept a WPA key as it is communicated between stations and access points.
SSL (Secure Sockets Layer)
A security protocol that uses certificates for authentication and encryption to protect web communication.
Guest Network
A separate wireless network created through a Wi-Fi router or access point to protect a private network while still providing guests with access to the Internet.
Caching DNS server
A server that accesses public DNS data and caches the DNS information that it collects. This server receives DNS queries from local network clients and works to resolve them by contacting other DNS servers for information.
Protocols
A set of rules governing the exchange or transmission of data between devices.
spectrum analyzer
A software tool that assesses the characteristics (for example, frequency, amplitude, and the effects of interference) of wireless signals.
rack system
A standardized frame or enclosure for mounting multiple electronic equipment and devices
ICMP (Internet Control Message Protocol)
A supporting protocol in the Internet protocol suite. Used by network devices, like routers, to send error messaged and operational information indicating, for example, that a request service is not available or that a host or router could not be reached. (Finding the best route for a packet when traversing several networks)
multicast address
A type of address in the IPv6 that represents multiple interfaces, often on multiple nodes. An IPv6 multicast address begins with the following hexadecimal field: FF0x, where x is a character that identifies the address's group scope.
Network Address Translation (NAT)
A technique that allows private IP addresses to be used on the public Internet.
PBX (private branch exchange)
A telephone switch used to connect and manage an organization's voice calls.
dynamic IP address
A temporarily assigned IP address usually provided by an ISP
Shielded Twisted Pair (STP)
A twisted pair cable that has an aluminum shield inside the plastic jacket that surrounds the pairs of wires.
crossover cable
A twisted pair patch cable in which the termination locations of the transmit and receive wires on one end of the cable are reversed.
toner and probe kit
A two-piece tool that includes both a tone generator and a tone locator. Used together, they can help locate the termination of a wire pair.
Rollover Cable
A type of cable in which the terminations on one end are exactly the reverse of the terminations on the other end. It is used for serial connections between routers and consoles or other interfaces.
Simplex
A type of transmission in which signals may travel in only one direction over a medium.
Diffraction
A wireless signal is diffracted or split into secondary waves whenbit encounters an obstruction. the secondary waves continue to propagate in the direction in which they were split. *appear to be bending*
hub
Accepted signals from a transmitting node and repeated those signals to all other connected nodes in a broadcast fashion. They are outdated but once served as the central connection point for a star topology
cable management
Adding new cables to a data room, repairing defective cable ends, or installing a data outlet
Private IP address
Addresses used by organizations for nodes that need IP connectivity only within their enterprise network, but not external connections to the Internet. 10.0.0.0 through 10.255.255.255 172.16.0.0 through 172.31.255.255 192.168.0.0 through 192.168.255.255
Time Domain Reflectometer (TDR)
Advanced cable tester that tests the length of cables and their continuity or discontinuity, and identifies the location of any discontinuity due to a bend, break, unwanted crimp, etc. by measuring the way the signal it issues bounces back.
MDF (main distribution frame)
Also known as the (mc) main cross connect, the MDF is the centralized point of interconnection for an organization's LAN or WAN. In practice the MDF can refer either to the racks holding the network equipment or the room that houses both the racks and the equipment.
Evil Twin
An AP set up by an attacker to mimic an authorized AP and capture transmissions, so a user's device will unknowingly connect to this evil twin instead.
SMTP (Simple Mail Transfer Protocol)
An Internet-standard protocol for sending email messages between servers on IP networks. Because SMTP is generally used to send messages from a mail client to a mail server, you should specify both the POP or IMAP server and the SMTP server when configuring an email application.
omnidirectional antenna
An antenna that detects signals from all directions equally.
remote application
An application that is installed and executed on a server, and is presented to a user working at a client computer.
four-post rack
An equipment rack consisting of four vertical side posts to which equipment is attached via brackets incorporated in the posts.
Multimeter
An instrument for measuring the properties of an electrical circuit.
Open Shortest Path First (OSPF)
An interior gateway routing protocol developed for IP networks based on the shortest path first or link-state algorithm. -Supports large networks(no hop limits on transmission path) -Complex Algorithms to find the best path for data to travel -Shared data(maintains database of other routers links) -low overhead, fsst convergence(more memory and cpu power for calculations but network bandwidth to a minimum) -Supported by all modern routers
infrastructure
An intervening connectivity device a WAP or AP accepts wireless signals feom multiple nodes and retransmits them to the rest of the network
CWDM (coarse wavelength division multiplexing)
Lowers cost by spacing frequency bands wider apart to allow for cheaper transceiver equipment
broadband
Any digital data connection that can transmit information faster than standard dial-up by using a wider band of frequencies.
OSI Layer 7 (Data)
Application Layer describes interface between two applications on separate computers. Protocols= HTTP SMTP, POP3, IMAP4, FTP, Tellnet, and RDP. These protocols are used by programs that either provide services to a user(browser/server), or to the system
Class E
Assigned to Research 240-254
FDM(Frequency Division Multiplexing)
Assigns different frequencies to create multiple frequency bands, each used by a subchannel so that multiple signals can transmit on the line at the same time.
STDM (statistical time division multiplexing)
Assigns time slots to nodes but then adjusts these slots according to priority
Common DNS Server software
BIND (Berkeley Internet Name Domain) is by far the popular DNS server software.
patch panels- use patch panels to organize and connect lines-why?
Because a patch panel keep lines organized as they run from walls to racks to network devices, and they make it easy to switch out patch cables of variable lengths when devices are moved or changed
What is a connection orientated protocol?
Before TCP transmits data, it ensures that a connection or session is established, similar to making sure someone is listening on the other end of a phone call before you start talking.
UDP (User Datagram Protocol)
Connectionless means that it does not guarantee delivery by first connecting and checking whether data is received...It is used for broadcasting and monitoring network traffic
What is the access method for wireless networks?
CSMA/CA
twisted-pair cable
Cables made of copper wires that are twisted around each other and are surrounded by a plastic jacket (such as traditional home phone wire). *more twists per foot in a pair of wires the more resistant the pair will be to crosstalk or noise.
UTP- Common Sizes/types of UTP
Cat 3- 10 mbps, 16mhz, used for 10 mbps ethernet or 4 mbps rarely used fornmodern network Cat 5- 100 Mbps, 100 MHz, Required minimum standard for fast Ethernet Cat 6- 10 Gbps, 250 MHz Includes a plastic core to prevent crosstalk between twisted pairs in cable. can also have foil insulation that covers the bundle of wire pairs, and a fire resistant plastic sheath Cat 6a- 10 Gbps, 500 MHz. Cat6a cables often include shielding around all pairs for better shielding from crosstalk and interference Cat 7- 10 Gbps, 600 MHz Each wire pair is shielded and there is shielding right under the cable jacket that is around all 4 wire pairs. Different type of connector is used Cat 7a- 40-100 Gbps, 1000 Mhz. ISO standards are still being drafted
Documentation Guidelines
Central location- keep your cable plant documentation in a centrally accessible location that include locations, installation dates, lengths, and grades of installed cable. labeling- every data jack or port, patch panel or punchdown block, connector or circuit. Color coding- color code cables for different purposes and document -Update documentation as you make changes to the network the more you document the easier it will be to troubleshoot move or add cable segments in the future
Where can IPv4s be located?
Either publicly on the internet or privately on private networks
SSH (Secure Shell)
Command in Linux that creates a secure channel between 2 computers
Domain Information Groper (DIG)
Command-line tool in non-Windows systems used to diagnose DNS problems. Use dig to query DNS nameservers for info about host addresses and other DNS records
Public IP address
Classes AB and C that are available for use on the internet
What is an Edge or Border router? Use/function?
Connect an autonomous system with an outside network, also called an untrusted network. For example the router connects a business with its ISP to an edge router.
FCC(Federal Communications Commission) control/regulation
Controls wireless spectrums use(airwaves). the FCC grants organizations in different locations exclusive rights to use each frequency and specifies which frequency ranges can be used for what purposes
Destination Network Address Translation (DNAT)
Converts a destination IP address to another -used to convert externally accessible IP addresses to an internal address
H.323
Creation of connections for multimedia session...make a connection between hosts prior to communicating multimedia data
Significance of 0.0.0.0
Currently unassigned
ipconfig/all
Displays TCP/IP configuration information for each network Adapter
MOU (memorandum of understanding)
Documents the intentions of two or more parties to enter into a binding agreement, or contract.
DNS
Domain Name System- name resolution
DHCP
Dynamic Host Configuration Protocol- Distribution of IP addresses on a network-client to server messages/server to client messages
DHCP
Dynamic Host Configuration Protocol. A service used to dynamically assign TCP/IP configuration information to clients. DHCP is often used to assign IP addresses, subnet masks, default gateways, DNS server addresses, and much more.
bend radius
Each type of cable has this, which is the radius of the maximum arc into which you can loop a cable without impairing data transmission
ESD (Electrostatic Discharge)
Esd strap for protection... danger includes catastrophic failure(destroys the component beyond use) and upset failure (shorten the life of a component and/or cause intermittent errors
MSDS (Material Safety Data Sheet)
Explains how to properly handle substances such as chemical solvents and how to dispose of them
Link-local unicast
FE80::/64
IPv6 auto-configuration
FE80::/64 is the prefix(first 64 bits), the last 64 bits can be two ways..randomly generated or generated from the MAC address..mac addresses are 48 bits so they are converted to the 64-bit standard, then the cpu checks to make sure IP is unique on internet, the computer asks if a router on the network can provide configuration info
FTP (file transfer protocol) server
FTP is a client server application that transfers files between to computers, and it primarily uses FTP (File Transfer Protocol)
What is flow control? What is an example of flow control?
Flow control is the process of gauging the appropriate rate of transmission based on how quickly the recipient can accept data. For example suppose a receiver indicates its buffer can handle up to 4000 bytes. The sender will issue up to 4000 bytes in one or many small packets and then pause, waiting for an acknowledgment, before sending more data.
Header fields for the 802.11 fields
Frame control, Duration, Address 1, Address 2, Address, Sequence control, Address 4
war chalking
Hackers draw symbols with chalk on the sidewalk or wall near a vulnerable AP To make it known to other hackers
MAC address (Media Access Control)
Hardware addresses of the source and destination NICs.. embedded on every network adapter on the globe
Logical Topology
Has to do with software, how access to the network is controlled, including how users and programs initially gain access to the network and how specific resources like applications and databases are shared on the network.
root server
Hold information used to locate the TLD servers.
TXT (Text) record
Holds any type of free-form text. it might contain text designed to be read by humans regarding network, server, or accounting issues. Most often its used by SPF(Sender Policy Framework) and DKIM (DomainKeys Identified Mail)
HTTPS
Hypertext Transfer Protocol Secure- Secure implementation
HTTP
Hypertext Transfer Protocol- Requests between web servers and web clients
who is the authority on Domain Names?
ICANN
DWDM(Dense wavelength division multiplexing or dense WDM)
Increases the number of channels provided by normal WDM to between 80 and 320 channels. Dense WDM can be amplified en route and is tylically used on high bandwidth or long distance WAN links
ICMP
Internet Control Message Protocol- A lightweight protocol used to carry error messages and information about a network
what is a directional antenna/unidirectional
Issues wireless signals along a single direction. This type is used when the source needs to communicate with one destination, as in a point-to-point link, or in a specific area. A satellite downlink (for example, the kind used to receive TV signals) uses directional antennas.
What is a distance-vector routing protocol? Example(s)?
It calculates the best path to a destination on the basis of the distance to that destination. Some distance-vector routing protocols factor only the number of hops to the destination, whereas others take into account route latency and other network traffic characteristics. RIP, RIPv2 and EIGRP are distance-vector routing protocols.
What is a Link-state routing protocol? Example(s)?
It enables routers to communicate beyond neighboring routers, after which each router can independently map the network and determine the best path between itself and message's the network, but can also be more complex to configure and troubleshoot. OSPF and IS-IS are link state routing protocols.
How does event viewer help with IP Address problems?
It identifies the problem and advises how to troubleshoot the problems your computer is facing
ipconfig /renew
Leases a new IP address from a DHCP server
LDAP
Lightweight Directory Access Protocol- Access to network based directories...accessing network based directories
ping6
Linux computer running IPv6, use ping6 to verify whether and IPv6 host is available. When you ping a multicast address with ping6, you get responses from all IPv6 hosts on that subnet
Attenuation
Loss of power in a signal as it travels from the sending device to the receiving device
Functions of Mac and LLC sublayer
MAC- Lower portion of the Data Link Layer that is specifically involved with managing MAC addressesin message frames. LLC- logical link control is primarily concerned with multiplexing, flow and error control and reliability
2 data link sublayers
Mac Sublayer. LLC Sublayer
ifconfig down
Marks the interface, or network connection, as unavailable to the network.
My Traceroute (mtr)
Terminal command in Linux that dynamically displays the route a packet is taking. Similar to traceroute.
Airflow Consideration for racks
Minimizing cable clutter to prevent airflow blockages...airflow is designed to move from front to back, there is a hot and cold aisle layout so it pulls cold air from vents nearby..hot air aisles are used to direct heated air away from the racks into exhaust vents for cooling
Inventory Management
Monitoring and maintaining of all the assets that make up a network.
Disadvantages of a client-server network
More complicated and expensive.
Mac address location
NIC's circuit board or on a sticker attached to some part of the NIC, command ipconfig
Border Gateway Protocol (BGP)
Path vector routing protocol-Communicates via BGP specific messages that travel between routers over TCP sessions -Spans multiple autonomous systems and is used by edge and exterior routers on the internet
OSI layer 1(Bit)
Physical Layer, responsible only for sending bits via a wired or wireless connection.
Registered Ports
Ports ranging from 1024 to 49151 and can be used temporarily by processes for nonstandard assignments for increased security
POP3
Post Office Protocol 3- Incoming email messages(downloaded messages)
MAC filtering
Prevents the AP from authenticating any device whose MAC address is not listed by the network administrator.
PPE (personal protective equipment)
Protective equipment that blocks exposure to a pathogen or a hazardous material.
ARP (Address Resolution Protocol)
Protocol in the TCP/IP suite used with the command-line utility of the same name (arp) to determine the MAC address that corresponds to a particular IP address.
IPv6 (Internet Protocol version 6)
Protocol in which addresses consist of eight sets of four hexadecimal numbers,(128 bits) each number being a value between 0000 and FFFF, using a colon to separate the numbers. Here's an example: FEDC:BA98:7654:3210:0800:200C:00CF:1234.
Telnet Service
Protocol used by the telnet client-server command-line application to allow an administrator or other user to "remote in" or control a computer remotely. Telnet is not encrypted and this is not secure.
What is RTS/CTS?
RTS/CTS is an optional protocol you can use to ensure that packets are not inhibited.
"U" or "RU"
Rack units used to measure rack height
switch
Receives incoming data from one of its ports and redirects it to another port or multiple ports that will send the data to its intended desination(s).
What is an Exterior router? Use/function?
Refers to any router outside the organizations AS. such as a router on the internet backbone.
SIP
Session Initiation Protocol- Creation of encrypted/unencrypted connections for multimedia session...make initial connection between hosts but that does not participate in data transfer during the session
OSI layer 5(data)
Session layer, describes how data between applications is synced and recovered applications don't arrive intact at the receiving application.
FHSS (Frequency Hopping Spread Spectrum)
Short bursts of data are transmitted on a particular frequency within the band and the next burst goes to the next frequeny in the sequence.
SMTP
Simple Mail Transfer Protocol- Outgoing email messages
wireless analyzer
Software that can evaluate Wi-Fi network availability as well as help optimize Wi-Fi signal settings or help identify Wi-Fi security threats.
structured cabling
Standards defined by TIA/EIA that define methods of organizing the cables in a network for ease of repair and replacement.
What is a common procedure?
Submit a change Request document follow process, change is project managed, provide documentation, close the change
What documentation is necessary for change management?
Submit a change request document.
The 66 block and 110 block
The 66 block (older type/used in telephony) The 110 block (newer type/used in networking)
OSI Layer 2 (Frame)
The Data Link layer identifies devices on the Physical layer. MAC addresses are part of the Data Link layer. Bridges operate at the Data Link layer.
What is CSMA/CD? Steps?
The Mac method used by nodes for arbitration on the network. 1.)Carrier sense refers to an Ethernet NIC listening and waiting until no other nodes are transmitting data 2.)Multiple Access refers to several nodes accessing the same network media. 3.)Collision refers to what happens when nodes attempt a transmission at the same time.
OSI Layer 3(Packet)
The Network layer moves messages from one node to another until they reach the host. Routers operate at the Network layer. IP, ICMP, ARP operate at the Network layer. If a Network layer protocol is aware that a packet is larger than the maximum size it will divide the packet into smaller pieces(fragmentation)
OSI layer 6 (Data)
The Presentation layer, Responsible for remformatting, compressing, and or encrypting data in a way that the operating system on the receiving end can read.
What is a 3-way handshake? Why is it useful ... or what is the purpose?
The TCP three-way hand shake establishes a session before the TCP transmits the actual data, such as an http request for a web page.
Data port standard
The TIA/EIA standard calls for each wall jack to contain at least one data outlet and voice outlet
TLD (top-level domain)
The highest-level category used to distinguish domain names-for example, .org, .com, and .net. A TLD is also known as the domain suffix.
Bandwidth
The amount of data that can be transmitted over a network in a given amount of time.
DMZ (demilitarized zone)
The area between two firewalls.
authoritative servers
The authority on computer names and their IP addresses for computers in their domains.
Backbone Wiring
The backbone consists of the cables or wireless links that provide interconnection between the entrance facility and MDF, and between MDFs and IDFs.
FQDN (Fully Qualified Domain Name)
The host name combined with the host's domain name. for example dlbrown.hacc.edu
Active directory
The centralized directory database that contains user account information and security for the entire group of computers on a network.
IMAP4 (Internet Message Access Protocol, version 4)
The client application manages the email while it's stored on the server
What is Ethernet? Layer 2 Standard
The current Ethernet standard, developed by DEC, Intel, and Xerox (abreviated as DIX) before IEEE began to standardize Ethernet.
Captive Portal
The first page that a new client sees in the new browser when connecting to the guest network, and usually requires the user to agree to a set of terms and conditions before gaining further access to the guest network.
cladding
The glass or plastic shield around the core of a fiber-optic cable. Cladding reflects light back to the core in patterns that vary depending on the transmission mode. This reflection allows fiber to bend around corners without impairing the light-based signal.
MAC Address format-Device ID
The last 24 bits of the MAC address identify the device itself
OSHA (Occupational Safety and Health Administration)
The main federal agency charged with safety and health in the workplace
What is a Collision Domain?
The portion of a network in which collisions can occur. Hubs connecting multiple computers to a star-bus topology resulted in massive collisions.
OS (Operating System)
The primary form of software running on a computer that organizes tiles and folders as well as telling the hardware how to interact with the user and other software.
System Life Cycle
The process of designing, implementing, and maintaining an entire network
network mapping
The process of discovering and identifying the devices on a network.
name resolution
The process of discovering the IP address of a host when the FQDN is known.
What is a sequence number? Purpose?
The segment is identified by sequence number 3043958669
host name
The unique name given to a network node on a TCP /IP network. Example dlbrown
Encryption
The use of an algorithm to scramble data into a format that can be read only by reversing the algorithm - that is, by decrypting the data.
What is checksum? purpose?
The valid outcome of the error-checking algorithm used to verify the segment's header is 0x206a. when computer A receives this segment, it will perform the same algorithm, and if the result matches, it will know the TCP header arrived without damage.
ICMPv6
The version of ICMP used with IPv6 networks. ICMPv6 performs the functions that ICMP, IGMP, and ARP perform in IPv4. It detects and reports data transmission errors, discovers other nodes on a network, and manages multicasting.
horizontal wiring
The wiring that connects workstations to the closest data closet. 90 m is max distance unless its copper TP which is 100m
secondary DNS server
the backup authoritative name server for the organization.
OSI layer 4 (Segment/Datagram
Transport Layer, responsible for transmitting application layer payloads from one application to another. The two main transport layer payloads are TCP, which guarantees delivery, and UDP, which does not.
TFTP
Trivial File Transfer Protocol- Simple File Transfer...most commonly used by computers as they are booting up to request config files from another computer on the local network
169.254.0.1 - 169.254.255.254
Used to create an APIPA address when a computer configured for DHCP first connects to the network and is unable to lease an IPv4 address from the DHCP server
How does a Hub operate in an Ethernet Network?
When data comes in a port, it Sends data to all nodes that are connected.
How does a SWITCH operate in an Ethernet Network?
When data comes in a port, it consults MAC table to locate Destination MAC address and sends data only to 1 port that has that MAC address.
passive scanning
When the AP takes initiative... Scanning for a wireless device that listens for a beacon frame for a set period of time. -the beacon frame contains information that a wireless node requires to associate itself with the AP includonfing networks transmission rate amd the SSID
HTTPS (Hypertext Transfer Protocol Secure)
When the http is layered on top of a encryption protocol such as SSL or TLS, which gives a secure transmission
know the process for RTS/CTS.
When using RTS/CTS, a source node issues an RTS signal to the access point requesting the exclusive opportunity to transmit. If the access point agrees by responding with a CTS signal, the access point temporarily suspends communiaction with all nodes in its range and waits for the source node to complete its transmission. When used, RTS/CTS decreases network efficiency. however, it can be worthwhile when transmitting large packets.
active scanning
When wireless client takes initiative.
peer-to-peer network model
Where each computer on a network is responsible for controlling access to resources with out centralized control.
Control Frames
Which 802.11 frame type is related to medium access and data delivery, and includes ACK and RTS/CTS frames?
ipconfig
Windows command that shows the IP configuration settings on a PC
Remote Desktop
Windows tool used to enable a local system to graphically access the desktop of a remote system.
IEEE 802.11
Wireless Ethernet standard more commonly known as Wi-Fi. (works at layers 1 and 2) wifi is a collection of wireless standards and their amendments, extensions, and corrections developed by committee
WDM(Wavelength division multiplexing)
Works with any fiber optic cable to carry multiple light signals simultaneously by dividing a light beam into different wavelengths or colors by a single fiber
How do you view a ARP table?
You can find the ARP table or ARP cache in the computer's hard drive.
channel bonding
____ is an 802.11n feature that allows two adjacent 20-MHz channels to be combined to make a 40-MHz channel.
racks
a framework used as a shelf or container.. ensuring adequate spacing, access, and ventilation for the devices they house
What is ZigBee? Use?
a low-powered, battery-conserving wireless technology. It is designed to handle small amounts of data is therefore ideal for use in ISM (industrial, scientific, and of data and therefore ideal for use in ISM (industrial, scientific, and medical) sensors.
Upgrade
a major change to the software package that enhances the functionality and features of the software, while also correcting bugs and vulnerability.
ad hoc
a small number of nodes closely positioned transmit directly to each other without an intervening connectivity device
punchdown tool
a tool that punches down twisted wire to complete a circuit.
IP address
a unique string of numbers separated by periods that identifies each computer using the Internet Protocol to communicate over a network.
LOS(Line of Sight)
a wireless signal ideally travels directly in a straight line from its transmitter to it intended receiver. LOS maximizes distance for the amount of energy used and results in reception of the clearest possible signal
What monitoring should be done in your cable plant
alerts to technicians can be sent when there is unacceptable temperatures, humidity, or airflow, texts when a secure door is left open, when the power supply is compromised, or when light and sound condition are unacceptable...these alarms can be programmed to escalate depending on the severity of the situation.
Star Topology
all devices connect to one central device (usually a switch) a star topology is the most common type of topology used in homes and offices.
Data Room
also called data closet, data center, equipment room, or telecommunications room, a data room is the enclosed space that holds network equipment.
EIGRP (Enhanced Interior Gateway Routing Protocol)
an advanced distance-vector protocol that combines some of the features of link state protocol andso is referred to as a hybrid protocol. Fast convergence time, low network overhead. Easier to configure and less CPU intensive. Limits unneccessary traffic between routers
What is a router?
an intelligent connecting device that examines each packet of data it receives and then decides which way to send it onward toward its destination
Attenuation
as with wired signals, wireless signals also experience attenuation. After a signal is transmitted, the farther it moves from the transmission source, the more it weakens.
DNS (Domain Name System)
associates computer names with IP addresses. maintains a directory of domain names and translates them to IP addresses.
Core
central fibers where data is transmitted. data is transmitted through the central fibers via pulsing light typically sent from one of two possible sources: light and LED
What icons are traditionally used for network diagrams?
cisco icons
power injector
device that can be used if my switch doesn't provide Power Over Ethernet to a device that needs it.
Termination-when terminating twisted-pair cabling, don't leave more than 1 inch of exposed (stripped) cable before a twisted pair termination because...
doing so increases the possibility of transmission interference between wires, a phenomenon called crosstalk.
Mesh Topology
every computer connects to every other computer; no central connecting device is needed...military applications, but today, they are typically used for things like home automation, smart HVAC control, and smart buildings.
TTL (Time to Live) field
field that identifies how long the record should be saved in a cache on a server.
Grounding- why pay attention to requirements
for safety purposes
dead zone
gaps in wifi coverage(can be pinpointed using heatmaps)
AAAA (Address) record
holds the name-to-address mapping for IPv6 addresses.
MX (Mail Exchanger) record
identifies a mail server and is used for email traffic.
SRV (Service) record
identifies the hostname and port of a computer that hosts a specific network service besides email, such as FTP or SIP.
Plenum cabling-if cable is run in a pleunum space, use plenum rated cable- why?
if you run cable in the plenum the area above the ceiling tile or below the subflooring make sure that cable sheath is plenum-rated and consult with local electric installation codes to be certain. Plenum-rated cable is coated with a flame-resistant jacket that produces less smoke than regular.. regular cabling is toxic when burned
Verifying IP Addresses on a Linux/Apple
ifconfig
NS (Name Server) record
indicates the authoritative name server for a domain. It's mostly used for delegating sub domains to other name servers.
Documentation- what is meant by documentation?
information of the network kept and managed by the network owners to assist with the awareness of all components within the infrastructure
How can you find IPv4 address of a machine? What command?
ipconfig/all
Where can this be located
ipconfig/all
TCP (Transmission Control Protocol)
makes a connection with the end host, checks whether data was received; called a connection-oriented protocol. Used by applications such as web browsers and email.
patch cable(straight through cable)
most common type of networking cable
RTT(Round Trip Time)
most common way to measure latency on data networks..length of time it takes for a packet to go from sender to receiver then back from receiver to sender
Physical Topology
mostly applies to hardware and describes how computers, other devices, and cables fit together to form the physical network
cross talk
occurs when one circuit picks up signals in another wire or cable
how do you set your PC with a static IPv4 Address?
open the internet Protocol Version 4(TCP/IPv4), and then click properties. From here you can manually assign a static IP address.
How do you set your PC to get an IPv4 Address from a DHCP Server?
open the internet Protocol Version 4(TCP/IPv4), and then click properties. From here you can turn it on find address auto.
Static Network Address Translation (SNAT)
provides a mapping between private IP address and any of the IP addresses belonging to the available public IP address pool.
pathping
provides information about network issues along a route. It sends multiple pings to each hop along a route then compiles the informstion intona single report
Telnet Protocol
provides terminal emulation that allows a personal computer or workstation to act as a terminal, or access device, for a server
use and advantage of repeater for digital signals
regenerates a digital signal in its original form without the noise it might have previously accumulated
ipconfig /release
releases the IP address when dynamic IP addressing is being used...disables computer's communications with the network until new IP address is assigned
What is a gateway of last resort? What is a default route?
router that accepts unroutable messages from other routers. The default route is the route to use if no other is a match.
What is meant by convergence time?
routing protocols are also rated on the time it takes to recognize a best path in the event of a change or network outage.
company standards - besides cabling standards, adhere to company standards on color codes, types of cables used, manufacturers, etc... - why?
so you can easily and quickly replace defective parts.
Gigabit Interface Converter (GBIC)
standard type of transceiver for gigabit ethernet connections
A (Address) record
stores the name-to-address mapping for a host. this resource record provides the primary function of DNS-to match host names to IP address, using IPv4 addresses.
slack in cable runs - always leave some slack in the cable runs - why?
stringing cable to tightly risks connectivity and data transmission issues.
ANT+
technology is based on the ANT protocol, which is an ad-hoc wireless protocol operating at about 2.4 GHz. gathers and tracks info from sensors that are embedded in devices can sync from multiple devices
primary DNS server
the authoritative name server for the organization, which holds the authoritative DNS database for the organization's zones.
NIC (Network Interface Card)
the device that enables a workstation to connect to the network and communicate with other computers
default gateway
the device that nodes on the network turn to first for access to outside networks
DNS zone
the domains that the organization is responsible for managing
Throughput
the measure of how much data is actually transmitted during a given period of time
IANA (Internet Assigned Numbers Authority)
the organization responsible for tracking the assignments of IP addresses, port numbers, and domain names IANA
What is a domain name?
the part of a network address that identifies it as belonging to a particular domain. for example hacc.edu
brute force attack
the password cracker tries every possible combination of characters
reassociation
the process of a station establishing a connection (or associating) with a different access point.
WPAN (Wireless Personal Area Network)
the purely wireless version of a LAN/PAN
What is route and show ip route? How are they useful? How do you use?
the route command allows you to view a hosts routing table. Here are some variations for different operating systems: Linux - route at shell prompt, Windows - route print at the command prompt, Cisco's IOS - show ip route.
Data Encapsulation
the separation of the representation of data from the applications that use the data at a logical level; a programming language feature that enforces information hiding
VoIP (Voice over Internet Protocol)
the use of any network to carry voice signals using TCP/IP protocols. Equipment needed includes VoIP gateway, switch(phones connected), and VoIP PBX
Reflection
the wave encounters an obstacle and reflects or bounces back towsrds its source. A wireless signal will bounce off objects whose dimensions are large compared with the signals average wavelength
avoid EMI - install cable at least 3 feet from fluorescent lights or sources of EMI - why?
this will reduce the possibility of noise interference that can affect your network's signals.
UTP
typically used for horizontal cabling(fiber used for backbone links)
Verify Continuity
use a cable tester to verify that each segment of cabling you install transmits data reliably..this practice will prevent from having to track down errors in multiple long stretches of cable
PTR (Pointer) Record
used for reverse lookups, to provide a host name when you know its IP address.
Infrared
used primarily to collect data through various sensors. infrared exists just below the spectrum that is visible to human eye with longer wavelengths than red light.
Routing Protocols
used to facilitate the exchange of routing information between routers
Scattering
when a wireless signal encounters an object that has small dimensions compared with the signal's wavelength, its diffused or scattered in multiple directions. Scattering is also related to the roughness of the surface a wireless signal encounters.
jitter
when latency between successive packets varies
AP location
wherever signal coverage and strength is maximized
cinch cables loosely - avoid cinching cables tightly - why?
you may squeeze the outer covering, this practice leads to difficult to diagnose data errors.
management frames
What 802.11 frame type is involved in association and reassociation, including probe and beacon frames?