CompTIA Security+ Question C-62

The security administrator needs to manage traffic on a layer 3 device to support FTP from a new remote site. Which of the following would need to be implemented?

A. Implicit deny
B. VLAN management
C. Port security
D. Access control lists

Answer: D

In the OSI model, IP addressing and IP routing are performed at layer 3 (the network layer). In this question we need to configure routing. When configuring routing, you specify which IP range (in this case, the IP subnet of the remote site) is allowed to route traffic through the router to the FTP server.

Traffic that comes into the router is compared to ACL entries based on the order that the entries occur in the router. New statements are added to the end of the list. The router continues to look until it has a match. If no matches are found when the router reaches the end of the list, the traffic is denied. For this reason, you should have the frequently hit entries at the top of the list. There is an implied deny for traffic that is not permitted.