Volume 2 Unit 1

Why must you remove the list of VLANs from a trunk when defining which VLANs can be trunked over a link?

Because all VLANs are trunked by default.

Why should all acquisitions of WLAN-enabled devices be WPA2 Enterprise certified?

Because current DOD policy requires all acquisitions of WLAN-enabled devices to be WPA2 Enterprise certified.

What are the advantages of a bus topology?

Bus networks are inexpensive to install, the bus topology works well for small networks (2-10 devices), bus networks use less cable than other physical topologies and you can easily add more workstations.

Division of the OSI model occurs into what two categories?

Data Transport (lower 1-4) layers Application (upper 5-7) layers

What assign a unique user-defined VLAN Identifier (VLAN ID) to each frame transported on a trunk link?

Frame identification, or tagging.

What command prompt do you set the enable password from?

Global configuration mode or Router(config)#.

Which CLI mode allows you to enter assign an IP address to the management VLAN of a switch?

Global configuration mode, Switch(config)#.

What are the two most widely used BOPs in the industry?

HDLC and SDLC.

What is the major difference between HDLC and SDLC?

HDLC's major difference over SDLC is that it ensures that the receiving station can distinguish information from garbage.

What are the two forms of control information used to exchange communications between peer OSI layers?

Headers and trailers.

At what layers do WAN protocols operate?

Lowest three layers (network, data link, and physical).

What do wireless access points use to make forwarding devisions?

MAC addresses.

An SNMP-managed network consists of what three key components?

Managed devices, agents and a network-management system (NMS).

What are the IPv6 two tunneling classes?

Manual and automatic.

What topology has cable segments from each computer connecting to a centralized component?

Star topology.

What do asynchronous data communications protocol data frames use for synchronization?

Start and stop bits.

Which command and mode allows configuration of a routing protocol on a router?

The router command from the global configuration mode, Router(config)#.

What does it mean to have dual stack router?

The router has both IPv4 and IPv6 protocols stacks running on it.

What does a Cisco router do if no configuration exists in NVRAM?

The router will bring up setup mode.

What are the advantages of a logical ring topology?

There are no collisions and the amount of data carried in one message is much greater than on a logical bus.

Why is limiting access to network infrastructure components, like routers, important?

These devices often protect segments of the network, and if compromised can be used for launching attacks against valuable network resources.

How does a switched network overcome flat network limitations?

Through the use of VLANs.

What can transport more than one VLAN through a single switch port?

Trunk link.

What areas will choosing one topology over another impact?

Type of equipment the network needs; capabilities of the equipment; the management of the network; and the growth of the network.

How many sets of 16 bit sections make up an IPv6 address?

8.

What are the disadvantages of a logical ring topology?

A broken ring will stop all transmissions and a device must wait for an empty token to be able to transmit.

What are some advantages of switch?

Switches have an internal processor, an operating system, memory, and several ports that enable other nodes to connect to it; have multiple ports and can make better use of limited bandwidth and prove more cost-efficient than bridges; each port on the switch acts like a bridge, and each device connected to a switch effectively receives its own dedicated channel; and because a switch limits the number of devices in a collision domain, it limits the potential for collisions.

What command configures a port for static VLAN membership?

Switchport mode access.

SNMP uses what TCP/IP ports?

TCP ports 161 and 162.

Which TCP/IP transport layer protocol establishes a connection between communicating nodes before transmitting the data?

TCP.

What three elements of the message block (frame) format can be contained in each BSC transmission?

(1) A header. (2) The text. (3) A trailer.

The selection of a subnet mask usually involves asking what two questions?

(1) How many routed subnets are required on the network? (2) What is the likely maximum number of hosts on any one of those subnets?

What are the four layers of the TCP/IP mode?

(1) Network Access Layer. (2) Internet Layer. (3) Transport Layer. (4) Application Layer.

What are the two most common hybrid topologies?

(1) Star-bus. (2) Star-ring.

What are some reasons for implementing DHCP?

(1) To make IP addressing transparent for mobile users. (2) To reduce the time spent on IP address management. (3) To reduce the potential for errors in assigning IP addresses. (4) To enable movement of network devices without having to change the TCP/IP configuration.

What is the total address length of an IPv6 address?

128 bits.

What is a logical topology?

A logical topology defines the way in which devices communicate, how devices access the network media and how data transmission occurs throughout the network.

What is a physical topology?

A physical topology is a "map," or description, of the physical layout of the network media and devices interconnect on a network.

What does a VPN provide?

A private tunnel through a public cloud (the Internet).

What does a typical router contain?

A typical router contains an internal processor, an operating system, memory, input and output jacks for different types of network connectors (depending on the network type) and usually a management console interface.

What protocol matches a known IP address for a destination device to a MAC address?

ARP.

What are the three distinct layers of the hierarchical model?

Access layer, distribution layer and the core layer.

Which hierarchical model layer requires high port density?

Access layer.

What tasks can all routers do?

All routers can: connect dissimilar networks, interpret Layer 3 addressing and other information (such as quality of service indicators), determine the best path for data to follow from point A to point B and reroute traffic if a primary path is down but another path is available.

What are some disadvantages of switches?

Although they contain buffers to hold incoming data and accommodate bursts of traffic, continuous and heavy traffic can overwhelm a switch and cause data loss.

What can an attacker with physical access to a router's flash memory card do?

An attacker with physical access to a router on your network can install a flash memory card, or replace an old one. They could then boot the router with their flash, thus causing the router to run their IOS version and configuration.

With both Layer 3 and 2 interfaces, you manually assign an interface to the EtherChannel by using what command?

Channel-group interface configuration command.

How does WPA2 offer increased security?

By implementing the Advanced Encryption Standard (AES).

How do you enter VLAN database mode to create a VLAN on a switch?

By using the vlan database command from the privileged EXEC mode.

How does the IEEE 802.11n specifications improve upon legacy wireless standards?

By utilizing multiple-input multiple-output antennas (MIMO).

What command creates the port-channel logical interface when configuring Layer 2 EtherChannels?

Channel-group interface configuration command.

IP address with a first octet from 192 to 223 are part of what IPv4 class?

Class C.

What are the disadvantages of a logical bus topology?

Collisions can occur easily and only one device may access the media at a time.

What command allows you to make global changes to the router from CLI?

Configure terminal or config t for short.

Which BOP frame field detects transmission errors?

Frame Check Sequence (FCS).

Ping uses ICMP services to send what two types of messages?

Echo request and echo reply messages.

Each EtherChannel can consist of up to how many compatibly configured Ethernet interfaces?

Eight.

What should you do to protect the confidentiality and integrity of a remote administration connection?

Encryption.

What technology is similar to token ring, but uses light instead of electricity to transmit data?

Fiber Distributed Data Interface (FDDI).

How does the organization of the collection of information occur MIB?

Hierarchically within the MIB, with each level having a branch leading into more information.

What are four examples of TCP/IP Internet layer protocols that function within the OSI network layer?

IP, ARP, RARP, and ICMP.

Which address is a 32-bit binary number, represented as a four-part decimal number, with each of the four parts separated by a period or decimal point?

IPv4 address.

What is the rule of thumb to distinguish physical from logical topologies?

If you can see it and touch it, it is physical; if you cannot see it or touch it, it is logical.

What are the three SDLC control field formats?

Information, Supervisory, and Unnumbered.

What mode and prompt allows configuration of a router interface?

Interface configuration mode or Router(config-if)#.

What are the advantages of a logical bus topology?

It is most widely implemented of the logical topologies, if a node is down, it does not bring down the entire network and additions and changes can occur easily without affecting other workstations.

What are the disadvantages of a bus topology?

It's no longer a recommended option for new installations, only a limited number of devices can be included, sharing the same cable means slower access time, it's difficult to isolate where a problem may be and if the back breaks, the network is down.

In autoconfiguration, a host device appends prefix information of its closest router to what?

Its own unique hardware or MAC address.

What are the seven layers of the OSI model?

Layer 1 - Physical Layer 2 - Data Link Layer 3 - Network Layer 4 - Transport Layer 5 - Session Layer 6 - Presentation Layer 7 - Application

The different subnets in a network connect via what type of device?

Layer 3 device (router).

Which IPv6 transition approach does not require a dual stack router?

Network Address Translation-Protocol Translation (NAT-PT).

What layer of the OSI model does the TCP/IP Internet Layer map to?

Network Layer.

What TCP/IP layer defines the access method for the network media and architecture?

Network access layer.

At what layers of the OSI model do LAN protocols operate?

Network and data link layers.

Routers operate at what layer of the OSI model?

Network layer (Layer 3).

What command turns an interface on?

No shutdown.

What protocols facilitate the automatic creation of EtherChannels by exchanging packets between Ethernet interfaces?

PAgP and LACP.

What mode does the Router# prompt indicate you are in?

Privileged EXEC mode.

What IPv4 protocol tunnels IPv6?

Protocol 41.

Identify and define the four common routing protocols.

RIP - Factors in only the number of hops between nodes when determining a path from one point to another. It does not consider network congestion or link speed. RIP is an interior routing protocol. OSPF - Used on interior or border routers; OSPF uses a more complex algorithm for determining best paths. OSPF imposes no hop limits on a transmission path. In OSPF, each router maintains a database of the other routers' links, and once notified of the failure of a given link, the router can rapidly compute an alternate path. EIGRP - Used on interior or border routers, was developed in the mid-1980s by Cisco Systems. It has a fast convergence time and a low network overhead, and is easier to configure and less CPU-intensive than OSPF. EIGRP also supports multiple protocols and limits unnecessary network traffic between routers. It also accommodates very large and heterogeneous networks. BGP - Used on border and exterior routers.

What are the four basic SNMP commands?

Read, write, trap, and traversal operations.

What should you remember when installing access points?

Remember to consider range limitations and readjust access point locations to allow for convergence.

In what topology does data flow in a circle, from station to station?

Ring topology.

What is the difference between routing and routed protocols?

Routing protocols are responsible for path determination and traffic switching. Routing protocols route routed protocols. Routed protocols are responsible for preparing the data for transmission on the network media.

Which command will show the current configuration of the router?

Show running-config or sh run.

What are two kinds of ring topologies?

Single ring and dual ring.

What command allows you to manually copy the router's configuration file from RAM to NVRAM?

The copy running-config startup-config command or the shortcut copy run start.

As a part of subnetting, which portion of the IP address do you borrow bits from to define various subnets?

The host portion.

With the exception of the layers on each of the model, what OSI model layers does each layer communicate with?

The layer directly above it, the layer directly below it and its peer layer in the other networked device.

What functions does a VPN concentrator perform?

VPN concentrators establishes tunnels, negotiates tunnel parameters, authenticates users, assigns user addresses, encrypts and decrypts data, manages security keys, manages data transfer across the tunnel manages data transfer inbound and outbound as a tunnel endpoint or router, and invokes various standard protocols to accomplish these functions.

What do VPN concentrators create to extend a network?

VPNs create tunnels to establish secure connections across a network such as the Internet.

Within the IP, what are the datagram field names?

Version, IHL, DiffServ Field, Total length, Identification, Flags, Fragment offset, TTL, Protocol, Header checksum, Source IP address, Destination IP address, Options, Padding and Data.

How should equipment be configured to help protect against denial of service attacks, and to allow support of the widest range of security services?

With the maximum amount of memory possible.

What must you do first in order to assign a switch port to a specific VLAN?

You must first create the VLAN on the switch if it does not already exist.

What must you identify when configuring serial interface connections on a router?

You must identify the DTE or DCE sides of the connection.