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?

access-list 10 deny 172.16.48.0 255.255.240.0
access-list 10 deny 172.16.144.0 0.0.7.255
access-list 10 deny 172.16.64.0 0.0.31.255
access-list 10 deny 172.16.136.0 0.0.15.255

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.

← Previous Question Next Question→

More Questions from Security

What router command allows you to determine whether an IP access list is enabled on a particular interface?
Which of the following commands connect access list 110 inbound to interface ethernet0?
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?
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?
Which of the following series of commands will restrict Telnet access to the router?
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?
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?
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

Discussion & Comments

No comments yet. Be the first to comment!

Join Discussion