Saturday, 23 June 2012

Cisco IOS Questions – Part 3


Here you will find answers to Cisco IOS Questions – Part 3

Note: If you are not sure about the boot sequence of a router/switch, please read my Cisco Router Boot Sequence Tutorial.
Question 1
Refer to the exhibit. A router boots to the prompt shown in the exhibit. What does this signify, and how should the network administrator respond?
rommon 1>
A. This prompt signifies that the configuration file was not found in NVRAM. The network administrator should follow the prompts to enter a basic configuration.
B. The prompt signifies that the configuration file was not found in flash memory. The network administrator should use TFTP to transfer a configuration file to the router.
C. The prompt signifies that the IOS image in flash memory is invalid or corrupted. The network administrator should use TFTP to transfer an IOS image to the router.
D. The prompt signifies that the router could not authenticate the user. The network administrator should modify the IOS image and reboot the router.

Answer: C
Explanation
If a Cisco router boots in ROMmon mode, it means:
+ The value of the configuration register is set to XXX(the boot field – fourth bit – is 0)
+ The router is unable to locate a valid Cisco IOS software image (you can use the “dir flash:” command in ROMmon mode to look for the IOS in the Flash then try to boot that flash with the “boot flash:<IOS image>” command).
If the IOS image is invalid or corrupted, the fastest way to re-install a new Cisco IOS software image on the router is to copy a new one from TFTP (with “tftpdnld” command).
Question 2
What should be done prior to backing up an IOS image to a TFTP server? (Choose three)
A. Make sure that the server can be reached across the network.
B. Check that authentication for TFTP access to the server is set.
C. Assure that the network server has adequate space for the IOS image.
D. Verify file naming and path requirements.
E. Make sure that the server can store binary files.
F. Adjust the TCP window size to speed up the transfer.

Answer: A C D
Question 3
Which two privileged mode cisco ios commands can be used to determine a cisco router chassis serial number? (choose two)
A. show inventory
B. show flash filesys
C. dir flash:|include chassis
D. show diag
E. show controllers

Answer: A D

Question 4
Which command helps a network administrator to manage memory by displaying flash memory and NVRAM utilization?
A. show secure
B. show file systems
C. show flash
D. show version

Answer: B
Question 5
A network administrator changes the configuration register to 0×2142 and reboots the router. What are two results of making this change? (Choose two)
A. The IOS image will be ignored.
B. The router will prompt to enter initial configuration mode.
C. The router will boot to ROM.
D. Any configuration entries in NVRAM will be ignored.
E. The configuration in flash memory will be booted.

Answer: B D
Explanation
The router bypasses the startup configuration stored in NVRAM during its boot sequence so the router will enter initial configuration mode. This feature is normally used during a password recovery procedure.
Question 6
Refer to the exhibit. For what two reasons has the router loaded its IOS image from the location that is shown? (Choose two)
Router1> show version
Cisco Internetwork Operating System Software
IOS ™ 7200 Software (C7200-J-M), Experimental Version 11.3tl997091S:1647S2)
[hampton-nitro-baseline 249]
Copyright (c) 1986-1997 by cisco Systems, Inc.
Compiled Wed 08-0ct-97 06:39 by hampton
Image text-base: 0×60008900, data-base: 0x60B98000
ROM: System Bootstrap, Version 11.1(11855) [beta 2], INTERIM SOFTWARE
BOOTPLASH: 7200 Software (C7200-BOOT-M), Version 11.1(472), RELEASE SOFTWARE (fcl)
Router1 uptime is 23 hours, 33 minutes
System restarted by abort at PC 0x6022322C at 10:50:SS PDT Tue Oct 21 1997
System image file is “tftp://112.16.1.129/hampton/nitro/c7200-j-mz”
cisco 7206 (NPE150) processor with 57344K/8192K bytes of memory.
<output omitted>
Configuration register is 0×2102
A. Router1 has specific boot system command that instruct it to load IOS from TFTP server.
B. Router1 is acting as a TFTP server for other routers.
C. Router1 cannot locate a valid IOS image in flash memory.
D. Router1 defaulted to ROMMON mode and loaded the IOS image from a TFTP sewer.
E. Cisco routers will first attempt to load a image from TFTP for management purposes.

Answer: A C
Explanation
When powered on, the router first checks its hardware via Power-On Self Test (POST). Then it checks the configuration register to identify where to load the IOS image from. In the output above we learn that the Configuration register value is 0×2102 so the router will try to boot the system image from Flash memory first.
But we also see a line “System image file is “tftp://112.16.1.129/hampton/nitro/c7200-j-mz”. Please notice that this line tells us the image file that the device last started. In this case it is from a TFTP server. Therefore we can deduce that the router could not load the IOS image from the flash and the IOS image has been loaded from TFTP server.
Note:
If the startup-config file is missing or does not specify a location, it will check the following locations for the IOS image:
+ Flash (the default location)
+ TFTP server
+ ROM (used if no other source is found)