Security problems
- 1. You want to create a standard access list that denies the subnet of the following host: 172.16.144.17/21. Which of the following would you start your list with?
Options- A. access-list 10 deny 172.16.48.0 255.255.240.0
- B. access-list 10 deny 172.16.144.0 0.0.7.255
- C. access-list 10 deny 172.16.64.0 0.0.31.255
- D. access-list 10 deny 172.16.136.0 0.0.15.255 Discuss
Correct Answer: access-list 10 deny 172.16.144.0 0.0.7.255
Explanation:
First, you must know that a /21 is 255.255.248.0, which is a block size of 8 in the third octet. Counting by eight, this makes our subnet 144 in the third octet, and the wildcard for the third octet would be 7 since the wildcard is always one less than the block size.
- 2. What router command allows you to determine whether an IP access list is enabled on a particular interface?
Options- A. show ip port
- B. show access-lists
- C. show ip interface
- D. show access-lists interface Discuss
Correct Answer: show ip interface
Explanation:
Only 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.
- 3. Which of the following commands connect access list 110 inbound to interface ethernet0?
Options- 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 Discuss
Correct Answer: Router(config-if)# ip access-group 110 in
Explanation:
To place an access list on an interface, use the
ip access-group command in interface configuration mode.
- 4. 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?
Options- 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 Discuss
Correct Answer: access-list 10 deny 192.168.160.0 0.0.31.255
Explanation:
The 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.
- 5. 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?
Options- 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 Discuss
Correct Answer: access-list 10 deny 172.16.192.0 0.0.31.255
Explanation:
First, 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.
- 6. Which of the following series of commands will restrict Telnet access to the router?
Options- A. Lab_A(config)#access-list 10 permit 172.16.1.1
Lab_A(config)#line con 0
Lab_A(config-line)#ip access-group 10 in - B. Lab_A(config)#access-list 10 permit 172.16.1.1
Lab_A(config)#line vty 0 4
Lab_A(config-line)#access-class 10 out - C. Lab_A(config)#access-list 10 permit 172.16.1.1
Lab_A(config)#line vty 0 4
Lab_A(config-line)#access-class 10 in - D. Lab_A(config)#access-list 10 permit 172.16.1.1
Lab_A(config)#line vty 0 4
Lab_A(config-line)#ip access-group 10 in
Discuss
Correct Answer: Lab_A(config)#access-list 10 permit 172.16.1.1
Lab_A(config)#line vty 0 4
Lab_A(config-line)#access-class 10 in
Explanation:
Telnet access to the router is restricted by using either a standard or extended IP access list inbound on the VTY lines of the router. The command
access-class is used to apply the access list to the VTY lines.
- 7. 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?
Options- A. show access-lists
- B. show interface Ethernet 0
- C. show ip access-lists
- D. show ip interface Ethernet 0 Discuss
Correct Answer: show ip interface Ethernet 0
Explanation:
The 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.
- 8. You want to create a standard access list that denies the subnet of the following host: 172.16.50.172/20. Which of the following would you start your list with?
Options- A. access-list 10 deny 172.16.48.0 255.255.240.0
- B. access-list 10 deny 172.16.0.0 0.0.255.255
- C. access-list 10 deny 172.16.64.0 0.0.31.255
- D. access-list 10 deny 172.16.48.0 0.0.15.255 Discuss
Correct Answer: access-list 10 deny 172.16.48.0 0.0.15.255
Explanation:
First, you must know that a /20 is 255.255.240.0, which is a block size of 16 in the third octet. Counting by 16s, this makes our subnet 48 in the third octet, and the wildcard for the third octet would be 15 since the wildcard is always one less than the block size.
- 9. Which of the following are valid ways to refer only to host 172.16.30.55 in an IP access list?
- 172.16.30.55 0.0.0.255
- 172.16.30.55 0.0.0.0
- any 172.16.30.55
- host 172.16.30.55
- 0.0.0.0 172.16.30.55
- ip any 172.16.30.55
Options- A. 1 and 4
- B. 2 and 4
- C. 1, 4 and 6
- D. 3 and 5 Discuss
Correct Answer: 2 and 4
Explanation:
The wildcard 0.0.0.0 tells the router to match all four octets. This wildcard format alone can be replaced with the
host command.
Programming
Copyright ©CuriousTab. All rights reserved.