Which ACL Can Be Used?

A

The correct answer is B. extended.

Access Control Lists (ACLs) are used to filter traffic and permit or deny traffic flow based on the criteria specified in the ACL. The different types of ACLs are standard, extended, reflexive, and dynamic.

Standard ACLs only examine the source IP address of traffic, while extended ACLs examine both the source and destination IP addresses as well as other parameters such as port numbers and protocols.

A reflexive ACL is a dynamic ACL that allows return traffic initiated from within the network in response to traffic that originated from the outside. It is created on the fly and is typically used to allow traffic for protocols that don't have well-known port numbers.

A dynamic ACL allows temporary access based on a set of criteria such as the time of day, source IP address, and authentication information. It is commonly used for remote access VPNs.

In this scenario, the network engineer wants to allow temporary access for a remote user with a specific username and password. This requires a dynamic ACL that is created based on the user's authentication information. However, none of the options in the answer choices describe a dynamic ACL, so this cannot be the correct answer.

The most appropriate ACL for this scenario is an extended ACL. An extended ACL can be used to filter traffic based on a wide range of criteria, including source and destination IP addresses, port numbers, and protocols. By specifying the remote user's username and password in the ACL, the network engineer can allow temporary access to the entire network over the internet.

Therefore, the correct answer is B. extended.