16 - Basic IPv4 ACLs

Question 1

What numbers can be used for Standard Numbered ACLs?

Answer 1

• 1 through 99

* 1300 through 1999

Question 2

What numbers can be used for Extended Numbered ACLs?

Answer 2

• 100 through 199

* 2000 through 2699

Question 3

What do Standard Numbered ACLs filter on?

Answer 3

Source IP address only

Question 4

As a rule where should Standard ACLs be placed?

Answer 4

Standard ACLs should be placed near to the destination of the packets

Question 5

What’s the difference between ‘show ip access-lists’ and ‘show access-lists’

Answer 5

show ip access-lists’ only shows info about IPv4 ACLs while ‘show access-lists’ shows info about all ACLs like IPv6 ACLs

Question 6

What show cmd will tell you if an ACL is present on an interface?

Answer 6

show ip interface gig0/0’

Question 7

How do you quickly calculate the wildcard mask?

Answer 7

subtract the subnet mask from 255.255.255.255

Question 8

How do you quickly calculate the range of addresses impacted by an ACL?

Answer 8

The IP address is the beginning of the range, then add the IP address to the WC mask to find the END of the range.