Security Questions and Answers

Exercise

Exercise 1
Exercise 2

Article

Q 1
If you wanted to deny FTP access from network 200.200.10.0 to network 200.199.11.0 but allow everything else, which of the following command strings is valid?

A)

access-list 110 deny 200.200.10.0 to network 200.199.11.0 eq ftp

access-list 111 permit ip any 0.0.0.0 255.255.255.255

B) access-list 1 deny ftp 200.200.10.0 200.199.11.0 any any

C) access-list 100 deny tcp 200.200.10.0 0.0.0.255 200.199.11.0 0.0.0.255 eq ftp

D)

access-list 198 deny tcp 200.200.10.0 0.0.0.255 200.199.11.0 0.0.0.255 eq ftp

access-list 198 permit ip any 0.0.0.0 255.255.255.255


Correct Option - D

ExplanationExtended IP access lists use numbers 100-199 and 2000-2699 and filter based on source and destination IP address, protocol number, and port number. The last option is correct because of the second line that specifies permit ip any any. (I used 0.0.0.0 255.255.255.255, which is the same as the any option.) The third option does not have this, so it would deny access but not allow everything else.

Report this question

Q 2
Which of the following commands connect access list 110 inbound to interface ethernet0?

A) Router(config)# ip access-group 110 in

B) Router(config)# ip access-list 110 in

C) Router(config-if)# ip access-group 110 in

D) Router(config-if)# ip access-list 110 in


Correct Option - C

ExplanationTo place an access list on an interface, use the ip access-group command in interface configuration mode.

Report this question

Q 3
What router command allows you to determine whether an IP access list is enabled on a particular interface?

A)   show ip port

B)   show access-lists

C)   show ip interface

D)   show access-lists interface


Correct Option - C

ExplanationOnly the show ip interface command will tell you which interfaces have access lists applied. show access-lists will not show you which interfaces have an access list applied.

Report this question

Q 4
You are working on a router that has established privilege levels that restrict access to certain functions. You discover that you are not able to execute the command show running-configuration. How can you view and confirm the access lists that have been applied to the Ethernet 0 interface on your router?

A)   show access-lists

B)   show interface Ethernet 0

C)   show ip access-lists

D)   show ip interface Ethernet 0


Correct Option - D

ExplanationThe only command that shows which access lists have been applied to an interface is show ip interface Ethernet 0. The command show access-lists displays all configured access lists, and show ip access-lists displays all configured IP access lists, but neither command indicates whether the displayed access lists have been applied to an interface.

Report this question

Q 5
You have created a named access list called Blocksales. Which of the following is a valid command for applying this to packets trying to enter interface s0 of your router?

A) (config)# ip access-group 110 in

B) (config-if)# ip access-group 110 in

C) (config-if)# ip access-group Blocksales in

D) (config-if)# blocksales ip access-list in


Correct Option - C

ExplanationUsing a named access list just replaces the number used when applying the list to the router's interface. ip access-group Blocksales in is correct.

Report this question

Q 6
You want to create a standard access list that denies the subnet of the following host: 172.16.198.94/19. Which of the following would you start your list with?

A) access-list 10 deny 172.16.192.0 0.0.31.255

B) access-list 10 deny 172.16.0.0 0.0.255.255

C) access-list 10 deny 172.16.172.0 0.0.31.255

D) access-list 10 deny 172.16.188.0 0.0.15.255


Correct Option - A

ExplanationFirst, you must know that a /19 is 255.255.224.0, which is a block size of 32 in the third octet. Counting by 32, this makes our subnet 192 in the third octet, and the wildcard for the third octet would be 31 since the wildcard is always one less than the block size.

Report this question

Q 7
You need to create an access list that will prevent hosts in the network range of 192.168.160.0 to 192.168.191.0. Which of the following lists will you use?

A) access-list 10 deny 192.168.160.0 255.255.224.0

B) access-list 10 deny 192.168.160.0 0.0.191.255

C) access-list 10 deny 192.168.160.0 0.0.31.255

D) access-list 10 deny 192.168.0.0 0.0.31.255


Correct Option - C

ExplanationThe range of 192.168.160.0 to 192.168.191.0 is a block size of 32. The network address is 192.168.160.0 and the mask would be 255.255.224.0, which for an access list must be a wildcard format of 0.0.31.255. The 31 is used for a block size of 32. The wildcard is always one less than the block size.

Report this question


Share This Page -