ACL Rule Configuration & Permissions Management 2

Question 1

Which ACL rule action causes the router to silently discard a packet without sending any notification to the source?

Accepted Answer

deny

Answer

The 'deny' action silently discards the packet, while 'reject' (used in some implementations) sends an ICMP unreachable message back to the source.

Question 2

When configuring a named extended ACL on a Cisco router, which command enters the ACL configuration mode?

Accepted Answer

ip access-list extended MYACL

Answer

'ip access-list extended MYACL' is the correct command to create and enter named extended ACL configuration mode on Cisco IOS.

Question 3

An administrator needs to permit only HTTPS traffic from a specific subnet. Which port number must be specified in the ACL rule?

Accepted Answer

443

Answer

HTTPS uses TCP port 443, so the ACL rule must specify destination port 443 to permit only encrypted web traffic.

Question 4

What does the wildcard mask 0.0.0.255 represent when used in an ACL?

Accepted Answer

Match all addresses in a /24 subnet

Answer

A wildcard mask of 0.0.0.255 means the last octet is irrelevant, so all 256 host addresses in a /24 subnet are matched.

Question 5

An ACL rule reads: 'deny tcp 192.168.1.0 0.0.0.255 any eq 23'. What traffic does this block?

Accepted Answer

Telnet traffic originating from the 192.168.1.0/24 subnet

Answer

Port 23 is Telnet; this rule denies TCP connections from any host in 192.168.1.0/24 to port 23 on any destination.

(ACL) Access Control Lists Practice Test