Router ACL Solution

D

The correct answer is D. A router ACL (Access Control List) is used to filter packets that are passing through a router.

Access Control Lists are used by routers to filter traffic based on specific criteria, such as source IP address, destination IP address, protocol type, port numbers, and more. By configuring an ACL on a router, network administrators can control the flow of traffic in and out of a network, allowing or denying specific types of traffic.

For example, an ACL can be configured to block traffic from certain IP addresses or subnets, or to allow traffic only from specific hosts or networks. This can help protect a network from malicious traffic or unauthorized access.

In summary, router ACLs are used to filter packets that are passing through a router, allowing network administrators to control the flow of traffic in and out of a network.