At the console terminal, you type

Router#show interface serial 1

You receive the following as part of the output:

Serial1 is up, line protocol is down

What could cause this? Choose four.

A. There are no keepalives

B. There is no clock rate

C. There is a wrong connector

D. In a back-to-back connection, the other end of the connection is

administratively down

E. The cable is disconnected

Answer: A, B, C, and D

If the cable were physically disconnected, then it would show Serial1 is down, protocol is down. When Serial1 is up, line protocol is down, it points to a layer 2 problem which could be no keepalives, no clock rate, wrong connector, or in a back-to-back connection, the other end of the connection is administratively down. If Serial1 is administratively down (line protocol is down) then the administrator manually disabled the interface.

Router interfaces are generally configured by the command:

Router(config)#interface type number

Which routers need more information for configuration?

A. For Cisco 7000, 7200, and 7500 series, define the interface by

slot, port number adapter, and port

B. For Cisco 4000 series, define the interface by slot, port

adapters, and port numbers

C. For Cisco 2500 series, define the interface by slot and

port number

D. There are no routers that need additional information,

all come with the exact feature set and will respond exactly

the same

Answer: A

Cisco 7000, 7200, and 7500 series routers have cards called Versatile Interface Processors (VIPs). These cards can have one or two slots for each port adapter. Each port adapter can have a number of interfaces. The numbering syntax is as follows:

type slot/port number adapter/port.

You have typed in "enable password Cisco" at the global configuration prompt. What did this command accomplish?

A. It sets "Cisco" as the password to the privileged EXEC mode

B. It sets "Cisco" as the password for any incoming Telnet sessions

C. It sets "Cisco" as the password for the console terminal

D. It sets "Cisco" the password for all access

Answer: A

This command sets "Cisco" as the password to the privileged EXEC mode.

You are working with a router, release 10.3+, what command loads a configuration file from a TFTP server directly into NVRAM?

A. configure terminal

B. copy tftp running-config

C. copy tftp startup-config

D. configure overwrite

Answer: C

To load a configuration file from a TFTP server directly into NVRAM, use the following command: copy tftp startup-config. The startup configuration file is stored in NVRAM.

Which command(s) display the backup configuration file that is stored in NVRAM? Choose two.

A. show startup-config

B. show config

C. show running-config

D. write term

Answer: A and B

The commands “show startup-config” (IOS 10.3+) and “show config” (IOS 10.2 and earlier) show the backup configuration file. The commands “show running-config” (IOS 10.3+) and “write term” (IOS 10.2 and earlier) show the active configuration parameters.

What will the "show version" command display? Choose four.

A. system hardware

B. software version

C. names and location of the configuration files

D. boot images

E. configuration parameters

Answer: A, B, C, and D

The “show version” command will display the system hardware, software version, names and location of the configuration files, and boot images. To see the configuration parameters, you need to use the command “show running-config” (IOS 10.3+) or “write term” (IOS 10.2 and earlier).

Which commands will display the active configuration parameters? Choose two.

A. show running-config

B. write term

C. show version

D. display term

Answer: A and B

IOS Release 10.2 or earlier uses “write term”, and IOS 10.3+ versions use “show running-config”.

The maximum number of commands that a router can save in its history is _______?

A. 10

B. 256

C. 128

D. 20

Answer: B

Use the terminal history size or history size to set the number of commands that are saved. The default is 10 and the maximum is 256. Type "terminal history size 256" (or however many lines you want to remember). To see how many commands are remembered use "show history".

A Cisco router provides many editing shortcuts. Which shortcut would you use to move to the beginning of a line?

A. Ctrl-E

B. Esc-B

C. Ctrl-A

D. Ctrl-F

Answer: C

Some of the editing commands are as follows:

Ctrl-A move to beginning of line

Ctrl-E move to end of line

Esc-B move to beginning of previous word

Ctrl-F move forward one character

Ctrl-B move back one character

Esc-F move forward one word

Which combination of keys will allow you to view the previous commands that you typed at the router?

A. Ctrl-P

B. ESC-P

C. Shift-P

D. Alt-P

Answer: A

Ctrl plus a key, moves either one character or one line. ESC moves one word. The combinations are:

Ctrl-A move to beginning of line

Ctrl-E move to end of line

Ctrl-F move forward one character

Ctrl-P previous command recall

Ctrl-N more recent command recall

Ctrl-B move back one character

Esc-B move to beginning of previous word

Esc-F move forward one word

TAB gives you entry completion.

When you first log into a router, you will be in user EXEC mode. The router waits for 10 minutes for input. You have decided that you want the router to not wait for input. Which command would you use?

A. exec-timeout 0

B. no exec-timeout 0

C. set timeout off

D. set timeout route

Answer: B

On a Cisco router, most commands can be cancelled by typing a “no” before the command and its set parameters.

Your router shows the following prompt:

Router (config)#

What mode are you in?

A. set timeout route global

B. interface configuration mode

C. RXBoot mode

D. configuration mode

Answer: D

You are in the global configuration mode. The interface configuration mode would show Router(config-mode)#. The RXBoot Mode shows Router<boot>. The setup mode gives you a prompted dialog.

You have typed “configure” at the # prompt to enter global configuration mode. Which methods can you use to return to the privileged EXEC mode? Choose three.

A. Type exit

B. Type end

C. Type bye

D. Press Ctrl-E

E. Press Ctrl-Z

Answer: A, B, and E

To leave the global configuration mode, you can type exit or end, or press Ctrl-Z.

You are configuring a router, which prompt tells you that you are in the privileged EXEC mode?

A. @

B. >

C. !

D. #

E. :

Answer: D

The privileged EXEC mode shows a # prompt, the user EXEC mode shows a >.

You connect your laptop to your Cisco router and see the following prompt:

rommon>

What has probably happened? Choose two.

A. The router did not find a valid system image

B. You interrupted the boot sequence during startup

C. You altered the settings of the configuration register

and rebooted the router

D. You typed "enable" at the prompt

Answer: A and B

> or rommon> are prompts that you receive if the router did not find a valid system image or you interrupted the boot sequence during startup. If you had altered the setting of the configuration register and rebooted, you would receive the "Router<boot>" prompt. If you typed enable at the prompt, you would enter the privileged EXEC mode and receive the # sign as a prompt.

Routers can be configured using several sources. Which of the following sources can be used? Choose three.

A. Console Port

B. Virtual Terminals

C. TFTP Server

D. Floppy disk

E. Removable media

Answer: A, B, and C

Routers can be configured from the console port, auxiliary port, virtual terminals, TFTP server, and a network management station.

You are configuring a Cisco router. You telnet in from your laptop which is connected to the console port. You see the following prompt:

Router>

Which mode are you in?

A. Privileged EXEC mode

B. User EXEC mode

C. ROM monitor mode

D. RXBoot mode

Answer: B

The User EXEC Mode shows the "Router>" prompt, the Privileged EXEC Mode shows a "Router#" prompt. Other modes are ROM Monitor Mode (> or rommon>), RXBoot Mode (Router<boot>) and the Setup Mode (this is a prompted dialog).

Which memory component on a Cisco router contains the dynamic system configuration?

A. Flash

B. NVRAM

C. RAM/DRAM

D. ROM

Answer: C

NVRAM contains the backup copy of the router's configuration. RAM/DRAM contains the dynamic configuration information; Flash contains a backup copy of the Cisco Internetwork Operating System (Cisco IOS) software. Flash can also contain multiple copies of the IOS software.

Select the routing protocol that uses balanced hybrid routing? Choose one.

A. IS-IS

B. IGRP

C. RIP

D. OSPF

E. Enhanced IGRP

Answer: E

Balanced hybrid routing uses distance vectors with more accurate methods to calculate distance and it uses topology changes to trigger routing database updates. Cisco's Enhanced Interior Gateway Routing Protocol (Enhanced IGRP) uses balanced hybrid routing.

How do you copy new variables to a TFTP server using IOS 10.2 or earlier?

A. copy running-config startup-config

B. copy running-config tftp

C. write network

D. write route

Answer: C

Use the command “write network” to copy new variables to a TFTP server using IOS 10.2 or earlier. Both "copy running-config startup-config" and "copy running-config tftp" are commands that are used with IOS 10.3+.

How do you copy new variables to the startup configuration file using IOS 10.2 or earlier?

A. write memory

B. copy running-config startup-config

C. copy running-config tftp

D. write route

Answer: A

Use the command “write memory” to copy new variables to a TFTP server using IOS 10.2 or earlier. Both "copy running-config startup-config" and "copy running-config tftp" are commands that are used with IOS 10.3+.

How do you copy new variables to a TFTP server for IOS 10.3+?

A. copy running-config startup-config

B. write memory

C. write network

D. copy flash tftp

Answer: D

The Cisco IOS configuration command "copy flash {rcp | tftp}" is used to copy configuration files from Flash memory to another destination. This command is new for IOS 10.3+.

How do you copy new variables to the startup configuration file for routers running Cisco IOS 10.3+?

A. copy running-config startup-config

B. write memory

C. write network

D. write route

Answer: A

The Cisco IOS configuration command "copy running-config startup-config" replaces the "write memory" command that was used in Cisco IOS versions released prior to IOS 10.3.

Which commands are considered last resort changes for IOS 10.2 or earlier? Choose two.

A. config memory

B. reload

C. config network

D. copy network

E. write erase

Answer: B and E

Cisco classifies changes as noninvasive, invasive and last resort. Noninvasive changes (config memory and config network) do not replace the saved configuration so you can return to it if your changes don't work. Invasive changes (copy network and reload) replace you running configuration. Last resort changes (write erase and reload) will return you to the default configuration.

What command do you use to copy a new configuration file to the startup file using IOS 10.2 or earlier?

A. copy running-config startup-config

B. write memory

C. write erase

D. copy configuration startup

Answer: B

"copy running-config startup-config" is the correct command for IOS 10.3+. "write memory" is used for pre-release IOS 10.3. "write erase" is used for pre-release 10.3 to erase the saved configuration.

You have made multiple changes to the running variables on your Cisco router (IOS 10.2 or earlier), what command do you use to verify those changes and at what prompt will you type the command?

A. Router#

B. show running-config

C. Router(config)#

D. show configuration

Answer: A and D

You should type “show configuration” at the Router# prompt for IOS 10.2 or earlier. Type "show running-config" at the Router# prompt for IOS 10.3+.

Which commands are considered last resort changes for IOS 10.3+?

A. erase start

B. reload

C. copy start run

D. copy TFTP start

E. copy TFTP run

Answer: A and B

Cisco classifies changes as noninvasive, invasive and last resort. Noninvasive changes (copy start run and copy TFTP run) do not replace the saved configuration so you can return to it if your changes don't work. Invasive changes (copy TFTP start and reload) replace you running configuration. Last resort changes (erase start and reload) will return you to the default configuration.

You have made multiple changes to the running variables on

a Cisco router (IOS 10.3+), what command do you use to

verify those changes and at what prompt will you type the

command?

A. Router#

B. show running-config

C. Router(config)#

D. show configuration

Answer: A and B

Type "show running-config" at the Router# prompt for IOS 10.3+. The command "show configuration" is used for pre-release 10.3.

You need to perform hardware maintenance on a specific

interface on your router. What command do you use to

disable the interface?

A. At the Router(config-if)# prompt, type shutdown

B. At the Router(config)# prompt, type shutdown

C. At the Router(config-if)# prompt, type stop interface

D. At the Router(config)# prompt, type stop interface

Answer: A

To disable an interface, type "shutdown" at the Router(config-if)# prompt. To restart it, type "no shutdown".

You have a series 4000 router that has an AUI option and a

10BaseT connector, the router defaults to the AUI option.

Which two commands are used to change the router to use the 10BaseT connector?

A. Router(config)#interface ethernet 2

B. Router(config-if)#media-type 10baseT

C. Router(config-if)#interface ethernet 2

D. Router(config)#media-type 10baseT

Answer: A and B

From the privileged EXEC mode:

1. Get into the global configuration mode by typing

"configure" at the Router# prompt.

2. Point the router to the specific interface by typing

"interface ethernet 2" at the Router(config)# prompt.

3. Set the media type by typing "media-type 10baseT" at the

Router(config-if) prompt.

4. To exit the global configuration mode to go back to the

privileged EXEC mode, type "exit", "end", or "Ctrl-Z".

You need to return a serial port to DTE status, what do you type at the configuration prompt?

A. Set the ring speed

B. clock rate DTE

C. clock rate T1

D. no clock rate

Answer: D

The command "no clock rate" is used to change an interface from DCE to DTE and to remove the clock rate.

You need to configure your router to support Token Ring with

early token release, which three commands would you need to enter.

A. Router(config)#interface tokenring 2/0

B. Router(config)#early-token release

C. Router(config-if)#ring-speed 16

D. Router(config-if)#interface tokenring 2/0

E. Router(config-if)#early-token release

Answer: A, C, and E

From the privileged EXEC mode:

1. Get into the global configuration mode by typing

"configure" at the Router# prompt.

2 Point the router to the specific interface by typing

"interface tokenring 2/0" at the Router(config)# prompt.

3 Set early token release AND the ring speed by typing

"early-token release" and "ring-speed 16" at the

Router(config-if) prompt.

4. To exit the global configuration mode to go back to the

privileged EXEC mode, type "exit", "end", or "Ctrl-Z".

The clock rate is set in bits per second, the bandwidth is

set in _________.

A. kbps

B. kbits

C. Mbits

D. Mbytes

Answer: A

The bandwidth in internetworking terminology is usually described in terms of "kbps" or kilobytes per second.

How do you configure a router to act as a DCE device?

A. Set the ring speed

B. Set the clock rate

C. Type "router DCE"

D. The router cannot be a DCE device

Answer: B

When the clock rate is set then the router becomes a DCE device.

The default clocking rate for a serial line is for a _______ line.

A. ISDN

B. T3

C. T1

D. PSDN

Answer: C

The default clock rate is set for a T1 line. A T1 line is 1.544 Mbps.

What is a back-to-back cable configuration?

A. When a modem isn't used

B. When the routers are both DTE devices

C. When the routers are both DCE devices

D. When one router functions as a DCE device

Answer: A and D

Routers are DTE devices but they can be configured as DCE devices so that they can provide a clocking signal. This is usually done when a modem is not in use.

At the console terminal, you type

Router#show interface serial 1

You receive the following as part of the output:

Serial1 is administratively down, line protocol is down

What could cause this?

A. There are no keepalives

B. There are keepalives

C. There is no clock rate

D. The interface has been manually disabled

Answer: D

If the cable were physically disconnected, then it would show Serial1 is down, line protocol is down. When Serial1 is up, line protocol is down, it points to a layer 2 problem which could be no keepalives, no clock rate, wrong connector, in a back-to-back connection, the other end of the connection is administratively down. If Serial1 is administratively down, line protocol is down, then the administrator manually disabled the interface.

At the console terminal, you type

Router#show interface serial 1

You receive the following as part of the output:

Serial1 is down, line protocol is down

What could cause this?

A. The cable is physically disconnected

B. There are no keepalives

C. There is no clock rate

D. There is a wrong connector

Answer: A

How do you find out information about other CDP (Cisco Discovery Protocol) devices that are connected to your network?

A. Type "show cdp" at the Router# prompt

B. Type "show cdp devices" at the Router# prompt

C. Type "show cdp neighbors" at the Router# prompt

D. Type "show cdp neighbors" at the Router(config)# prompt

Answer: C

The Cisco IOS privileged EXEC command "show cdp neighbors" will display information about neighboring routers connected on your network.

What is the correct prompt and command to configure the CDP (Cisco Discovery Protocol) timer?

A. cdp timer [seconds] at the Router# prompt

B. cdp timer [seconds] at the Router(config)# prompt

C. cdp holdtime [seconds] at the Router# prompt

D. cdp timer [seconds] at the Router(config-if)# prompt

Answer: B

The Cisco IOS global configuration command "cdp timer 'seconds'" at the Router(config)# prompt will specify how often the router will send CDP (Cisco Discovery Protocol) updates.

You have decreased the CDP time to 30 seconds, what impact will this have on your network? Choose two.

A. Router updates are quicker

B. Router updates are slower

C. Bandwidth usage will decrease

D. Bandwidth usage will increase

Answer: A and D

Router updates will be quicker but bandwidth usage will increase when the CDP time is decreased.

CDP (Cisco Discovery Protocol), by default, is set to discard CDP packets from other routers after 180 seconds. You have a network that has frequent changes to the router configuration files. What should you do to have the routers update quicker?

A. Configure the CDP holdtime to be less than the CDP timer

B. Configure the CDP holdtime to be more than the CDP timer

C. Configure the CDP holdtime to equal the CDP timer

D. Type no CDP holdtime

Answer: A

The default for the CDP timer is 60 seconds. To configure quicker updates, set the CDP holdtime to be less than the CDP timer.

You need to disable CDP on a specific router interface. How would you do this?

A. Type "no cdp run" at the Router(config)# prompt

B. Type "no cdp run" at the Router(config-if)# prompt

C. Type "no cdp enable" at the Router(config-if)# prompt

D. Type "no cdp enable" at the Router(config)# prompt

Answer: C

Type "no cdp enable" at the Router(config-if)# prompt to disable CDP on an interface. By default, CDP is automatically enabled on a router and its interfaces.

You need to disable CDP on your router. How would you do this?

A. Type "no cdp run" at the Router(config)# prompt

B. Type "no cdp run" at the Router(config-if)# prompt

C. Type "no cdp enable" at the Router(config)# prompt

D. Type "no cdp run" at the Router(config)# prompt

Answer: A

Typing the Cisco IOS global configuration command "no cdp run" at the Router(config)# prompt will disable CDP on the router.

You are an administrator connected to Router 1, which in turn is directly connected to Router 2 and Router 3. Router 4 is directly connected to Router 3. You need to obtain information from Router 4. How would you go about it?

A. telnet to Router 3

B. use CDP

C. type running-config

D. telnet to Router 4

Answer: D

CDP only works on directly connected routers so you would have to use a higher-layer protocol tool, such as telnet, to connect to the remote device.

The physical media that supports ______ can connect CDP devices.

A. Novell IPX

B. TCP/IP

C. SNAP

D. AppleTalk

Answer: C

SNAP (Subnetwork Access Protocol) works on the physical layer of the OSI reference model, the other protocols work on high layers.

Cisco Discovery Protocol (CDP) can discover any directly connected routers. On which OSI model layer does it work?

A. Presentation

B. Physical

C. Network

D. Session

E. Datalink

Answer: E

The Cisco Discovery Protocol (CDP) operates at the datalink layer of the OSI reference model. CDP is used by Cisco internetworking devices to advertise its location and existence in the network.

How do you cause a router to enter setup mode? Choose two.

A. Type "setup" at the Router# prompt

B. If the router is new or if NVRAM is corrupted, the router

will automatically enter setup mode

C. The router is always in setup mode

D. You can't force the router to enter setup mode

Answer: A and B

When you type the command "setup" at the Router# prompt, you will enter setup mode. Also, a corrupt or new software installation will automatically default to the router setup program.

You are copying a new system image file to your router from a tftp server because the present file has become corrupted. While the file is copying, you see a series of exclamation points. What do these mean?

A. Each exclamation point (!) means that one UDP segment has

successfully transferred

B. Each exclamation point (!) means that one TCP segment has

successfully transferred

C. Each exclamation point (!) means that there has been a

successful check run verification on a segment

D. The exclamation point is for informational purposes only

and has no real significance

Answer: A

Each exclamation point (!) means that one UDP segment has successfully transferred. Each V means that there has been a successful check run verification on a segment.

You need to copy the current system image file from the router to the network server, so you type "copy flash tftp" from the privileged EXEC mode. As the file is copying you need to cancel the copy, what series of keys will allow you to do this?

A. Ctrl + s

B. Ctrl + ^

C. Ctrl + h

D. Alt + ^

Answer: B

The key sequence, Ctrl + ^ will cancel the copy from flash memory.

You have typed "show flash". Under Name/status is "c2500-js-1.112-6.bin". What tells you that this is an enterprise image with extended capabilities?

A. 1

B. c2500

C. js

D. 112-6

E. bin

Answer: C

C2500 is the platform, js indicates that it is an enterprise image with extended capabilities, 1 indicates the file is re-locatable and not compressed, 112-6 indicates that it is IOS version 11.2-6, and bin indicates that it is a binary, executable file.

You have loaded all of your configuration files onto your router. When you restart the router, the configuration is not what you had planned on. What could have caused this problem?

A. Insufficient flash memory on the router

B. Inadequate processor speeds on the network server

C. Inadequate bandwidth on the network

D. You switched the wrong router off and on

Answer: A

Insufficient Flash memory on the router can cause unpredictable results. Flash memory is nonvolatile storage that can be erased and reprogrammed.

Which sources can be used for backup locations for software images for the Cisco router?

A. A bridge

B. A workstation

C. A host system

D. Another router

Answer: B, C, and D

Using the "boot system xxx" Cisco IOS global configuration command, you can choose various locations to store the system configuration startup files.

You need to ensure that the router always boots from NVRAM for a series 2500 router. Which command would you use?

A. config-register 0x2100

B. config-register 0x2102

C. config-register 0x2101

D. config-register 0x4101

Answer: B

The default is the hexadecimal number 0x2102 for the 2500 series routers and this boots from NVRAM. 0x2100 would cause the router to boot to ROM monitor mode, 0x2101 would cause the router to boot from ROM.

The "config-register" command is used at the global configuration prompt to tell the router where to get its boot system. You can have the router automatically enter the ROM monitor mode, boot automatically from ROM, or boot automatically from NVRAM. To do this you set the lowest four bits with the "config-register command". Select the

three bit configurations for the appropriate place to load the boot system commands?

A. To enter the ROM monitor mode, set the boot field to 0-0-0-0

B. To enter the ROM monitor mode, set the boot field to 0-0-0-1

C. To load the boot commands from NVRAM, set the boot field to any

number between 0-0-1-0 through 1-1-1-1

D. To load the boot commands from ROM, set the boot field to

0-0-1-0 through 1-1-1-1

E. To load the boot commands from ROM, set the boot field to 0-0-0-1

Answer: A, C, and E

Only A, C, and E are the correct configurations to load the boot system commands.

You need to provide backup methods for your Cisco router so that it will always look to your tftp server for boot system options. Which selection will cause the router to boot from the tftp server?

A. Router#configure terminal

Router(config)#boot system tftp test.exe 172.16.13.111

[Ctrl-Z]

Router#copy running-config startup-config

B. Router#configure terminal

Router(config)#boot system flash c2500-js-1

[Ctrl-Z]

Router#copy running-config startup-config

C. Router#configure terminal

Router(config)#boot system rom

[Ctrl-Z]

Router#copy running-config startup-config

D. Router#configure terminal

Router(config)#boot system test.exe 172.16.13.111

[Ctrl-Z]

Router#copy running-config startup-config

Answer: A

Only (A.) will boot from the tftp server, the other two boot from flash (B.) and ROM (C.).

What command will show you how the router is loading the

software image?

A. show bootstrap

B. show interfaces

C. show controllers

D. show version

Answer: D

The Cisco IOS "show version" EXEC command will display the configuration of the system hardware, configuration files, and boot images.

The first octet rule states that the class of an address can be determined by the numerical value of the first octet. Which addresses are INCORRECTLY paired with their class?

A. 1 to 126, Class A

B. 128 to 191, Class A

C. 1 to 126, Class B

D. 128 to 191, Class B

Answer: B and C

Address classes are: 1 to 126, Class A; 128 to 191, Class B, 192 to 223, Class C; 224 to 239, Class D; and 240 to 255, Class E.

In what order do most routers search for boot system commands?

A. First it looks to NVRAM, then to Flash memory, and finally

it will try a network alternative

B. First it looks to Flash, then to NVRAM, and finally it

will try a network alternative

C. First it looks to the network, then to Flash memory, and

finally NVRAM

D. First it looks to the network, then to NVRAM, then Flash

Answer: A

Boot order for Cisco routers:

1. NVRAM

2. Flash memory

3. Alternative location, such as a TFTP server.

The first octet rule states that the class of an address can

be determined by the numerical value of the first octet. Which addresses are INCORRECTLY paired with their class?

A. 240 - 255, Class D

B. 240 - 255, Class E

C. 224 - 239, Class D

D. 224 - 239, Class E

Answer: A and D

Address classes are: 1 to 126, Class A; 128 to 191, Class B, 192 to 223, Class C; 224 to 239, Class D; and 240 to 255, Class E.

Which IP Address Class is INCORRECTLY paired with its range

of network numbers?

A. Class A addresses include 192.0.0.0 through 223.255.255.0

B. Class A addresses include 1.0.0.0 through 126.0.0.0

C. Class B addresses include 128.0.0.0 through 191.255.0.0

D. Class C addresses include 192.0.0.0 through 223.255.255.0

E. Class D addresses include 224.0.0.0 through 239.255.255.0

Answer: A

Class A addresses include 1.0.0.0 through 126.0.0.0

Class B addresses include 128.0.0.0 through 191.255.0.0

Class C addresses include 192.0.0.0 through 223.255.255.0

Class D addresses include 224.0.0.0 through 239.255.255.0

Which IP Address Class can have 16 million subnets but support 254 hosts?

A. Class D

B. Class A

C. Class B

D. Class C

Answer: D

Possible Subnets IP Address Class Possible Hosts

254 A 16M

64K B 64K

16M C 254

Which IP Address Class can have 64,000 subnets with 64,000 hosts per subnet?

A. Class B

B. Class A

C. Class C

D. Class D

Answer: A

Possible Subnets IP Address Class Possible Hosts

254 A 16M

64K B 64K

16M C 254

There are two processes to pair MAC address with IP addresses. Which process finds an IP address from a MAC address?

A. ARP

B. RARP

C. RIP

D. IGRP

Answer: B

ARP (Address Resolution Protocol) maps an IP address to the MAC address, RARP (Reverse Address Resolution Protocol) maps the MAC address to the IP address. ARP and RARP work at the internet layer of the Internet Model or the network layer of the OSI model.

When the router runs out of buffer space, this is called ________.

A. Source Quench

B. Redirect

C. Information Request

D. Low Memory

Answer: A

Source quench is the process where the destination router, or end internetworking device will "quench" the data from the "source", or the source router. This usually happens when the destination router runs out of buffer space to process packets.

Which protocol carries messages such as destination Unreachable, Time Exceeded, Parameter Problem, Source Quench, Redirect, Echo, Echo Reply, Timestamp, Information Request, Information Reply, Address Request, and Address Reply?

A. FTP

B. UDP

C. TCP

D. TFTP

E. ICMP

Answer: E

ICMP (Internet Control Message Protocol) is a network layer internet protocol described in RFC # 792. ICMP reports IP packet information such as destination Unreachable, Time Exceeded, Parameter Problem, Source Quench, Redirect, Echo, Echo Reply, Timestamp, Information Request, Information Reply, Address Request, and Address Reply.

Which processes does TCP, but not UDP, use? Choose two.

A. Windowing

B. Acknowledgements

C. Source Port

D. Destination Port

Answer: A and B

UDP (User Datagram Protocol) does not use sequence or acknowledgement fields in transmission. UDP is a connectionless and unreliable protocol, since there is no delivery checking mechanism in the UDP data format.

Where would network testing be included in an IP packet?

A. IP Options field

B. Identification field

C. Type of Service field

D. Reservation field

Answer: A

Network testing would be included in the IP Options field in an IP packet.

What field tells the Internet layer how to handle an IP packet?

A. Identification

B. Type of Service

C. Flags

D. Frag Offset

Answer: B

The Type of Service field would tell the Internet layer how to handle an IP packet.

Two of the protocols that can be carried in the Protocol field of an IP packet are?

A. TCP

B. FTP

C. UDP

D. TFTP

Answer: A and C

The following are the fields in an IP segment, their length, and their definitions:

VERS (Version number - 16 bits)

HLEN (Number of 32-bit words in the header - 4 bits)

Type of Server (How the datagram should be handled - 32 bits)

Total Length (Total length of header and data - 32 bits)

Identification (Provide fragmentation of datagrams to allow

different MTUs in the internet - 4 bits)

Flags (Provide fragmentation of datagrams to allow

different MTUs in the internet - 4 bits)

Frag Offset (Provide fragmentation of datagrams to allow

different MTUs in the internet - 6 bits)

TTL (Time-To-Live - 6 bits)

Protocol (Upperlayer protocol sending the datagram - 16 bits)

Header Checksum (Integrity check on the header - 16 bits)

Source IP Address (32 bits)

Destination IP Address (32 bits)

IP Options (network testing, debugging, security and others - 4 bits)

Data (4 bits).

Which selection is the format of a UDP segment?

A. Source Port - 16 bits, Destination Port - 16 bits, Length

- 16 Bits, Checksum - 16 bits, Data

B. Destination Port - 16 bits, Source Port - 16 bits, Length

- 16 Bits, Checksum - 16 bits, Data

C. Source Port - 16 bits, Destination Port - 16 bits,

Checksum - 16 Bits, Length - 16 bits, Data

D. Source Port - 8 bits, Destination Port - 8 bits, Length -

8 Bits, Checksum - 8 bits, Data

Answer: A

The UDP format for a segment is as follows:

Source Port 16 bits

Destination Port 16 bits

Length 16 bits

Checksum 16 bits

Data xx bits

Which fields of an IP packet provide for fragmentation of datagrams to allow differing MTUs in the Internet? Choose three.

A. Identification

B. Flags

C. Total Length

D. Type of Service

E. Frag Offset

Answer: A, B, and E

The Identification, Flags, and Frag Offset fields provide for fragmentation of datagrams to allow differing MTU’s in the Internet.

What is the flow control mechanism called when the receiving TCP reports to the sending TCP the number of octets that it is willing to receive?

A. Sequence number

B. Handshake

C. Window size

D. Sequence window

Answer: C

The "window size" is the number of data segments that a sender can send without receiving an acknowledgement.

Two Hosts are setting up communication. Host A sends a SYN

control bit which says seq=100 ctl=syn; Host B replies with

seq=300 ack=101 ctl=syn, ack; Host A replies seq=101 ack=301

ctl=ack. What is the process called?

A. A three-way handshake

B. TCP simple acknowledgement

C. Window size setup

D. A two-way handshake

Answer: A

A three-way-handshake is detailed as follows:

Handshake #1 : Sender requests synchronization to receiver.

Handshake #2 : Acknowledgement of the synchronization

request.

Handshake #3 : Agreement that synchronization has taken

place.

Once the connection has been established, data can be transmitted.

Which is the INCORRECT pairing of a port number with an application?

A. TFTP, 69

B. SMTP, 25

C. DNS, 53

D. Telnet, 21

E. SNMP, 161

Answer: D

Telnet is incorrectly paired with port 21. It should be port 23. Other ports are: FTP, 21; SMTP, 25; DNS, 53, TFTP, 69: SNMP, 161.

Which statements about port numbers are correct?

A. Port numbers below 255 are for public applications

B. Port numbers from 256 - 1023 are assigned to companies

for saleable applications

C. Port numbers above 1023 are dynamically assigned by host

applications

D. Port numbers above 1023 are for public applications

E. Port numbers below 255 are dynamically assigned by host

applications

Answer: A, B, and C

Port numbers below 255 are for public applications. Port numbers from 256 - 1023 are assigned to companies for saleable applications. Port numbers above 1023 are dynamically assigned by host applications.

Which layer is responsible for flow control with sliding windows and reliability with sequence numbers and acknowledgments?

A. Application

B. Internet

C. Network Interface

D. Transport

Answer: D

The transport layer of the OSI model provides services that allow end systems to segment and then reassemble multiple data applications within the same data stream. Flow control is used to prevent buffer overflow at either end of the transmission.

Which are TCP/IP protocol-stack application layer protocols for file transfer?

A. TFTP

B. FTP

C. HPFS

D. NTFS

E. NFS

Answer: A, B, and E

The TCP/IP application layer protocols that are used for file transfer are:

TFTP - Trivial File Transfer Protocol

FTP - File Transfer Protocol

NFS - Network File System

You have entered the command "cdp entry routerB" at the Router# prompt. No information is returned, what could cause this?

A. The router's name is RouterB

B. You should have entered "cdp entry routerB.cisco.com"

C. You should have entered "cdp routerB.cisco.com"

D. You should have entered "cdp routerB"

Answer: A

Exact spelling is very important. The router’s name is case-sensitive.

You are logged into a router. What command would show you the IP addresses of routers connected to you?

A. show run

B. show cdp neighbors detail

C. show neighbors

D. show cdp

Answer: B

The correct command is "show cdp neighbors detail" to show the IP addresses of the routers connected to you.

Which are the layers of the TCP/IP protocol stack?

A. Process/Application

B. Host-to-Host

C. Internet

D. Session

E. Network Access

Answer: A, B, C, and E

The TCP/IP protocol stack (also known as the DoD model or Department of Defense model) has four layers much like the OSI reference model’s seven layers.

A comparison of the TCP/IP protocol stack and the associated

OSI reference model is as follows:

TCP/IP Conceptual Layers OSI Reference Model

Application Session, Presentation, Application

Host-to-Host Transport

Internet Network

Network Access DataLink, Physical

You perform an extended ping at the privileged EXEC prompt. As part of the display, you see "Set DF bit in IP header? [yes] :" What would happen if you answered no at the prompt.

A. The router would not fragment the packet

B. The router would direct the packet to the destination

it finds in its routing table

C. The router would fragment the packet

D. The router would send the packet to the next hop

router

Answer: C

"Set DF bit in IP header?" is a response to an extended ping at the router. If you answer yes (the default), the router will not fragment the packet. If you answer no, the router will fragment the packet.

You have typed "ping" 172.16.101.1 and get the following display:

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echoes to 172.16.101.1, timeout is 2 seconds:

.!!!!

What does the "." signify?

A. That all messages were successful

B. That one message timed out

C. That one message was successful

D. That one message completed in under the allotted timeframe

Answer: B

The possible responses from the ping command are:

! Successful receipt of an echo reply.

. Timed out waiting for a reply

U Destination unreachable

C Congestion-experienced packet

I Ping interrupted

? Packet type unknown

& Packet TTL exceeded