ACL Network Security & Traffic Filtering 5

Question 1

A Dynamic ACL (lock-and-key ACL) requires users to do what before gaining network access?

Accepted Answer

Authenticate via Telnet or SSH to trigger a temporary permit entry

Answer

Dynamic ACLs require users to authenticate via Telnet or SSH to the router, which then dynamically creates a temporary ACE permitting their traffic.

Question 2

What is the effect of applying an ACL to a VTY line with 'access-class 10 in'?

Accepted Answer

It restricts which IP addresses can establish a Telnet or SSH management session to the router

Answer

The 'access-class' command applied to VTY lines uses a standard ACL to restrict which source IP addresses are allowed to initiate Telnet or SSH management sessions.

Question 3

Which of the following is NOT a valid reason to use ACLs?

Accepted Answer

Encrypting traffic between two routers

Answer

ACLs filter and permit/deny traffic but do not provide encryption; encryption is handled by protocols like IPsec, SSL/TLS, or MACsec.

Question 4

An administrator sees 'access-list 1 permit 0.0.0.0 255.255.255.255' in the config. What traffic does this match?

Accepted Answer

All IP traffic from any source address

Answer

The combination of source address 0.0.0.0 and wildcard 255.255.255.255 matches all 32 bits as 'don't care,' which is equivalent to 'any' and permits all traffic.

Question 5

What is the significance of ACL sequence numbers in named ACLs on Cisco IOS?

Accepted Answer

They allow specific ACEs to be inserted between existing entries or deleted individually

Answer

Sequence numbers in named ACLs allow administrators to insert new ACEs at a specific position (e.g., sequence 15 between 10 and 20) or delete a specific ACE by its sequence number.

(ACL) Access Control Lists Practice Test

(ACL) Access Control Lists Practice Test

ACL Network Security & Traffic Filtering 5