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

Explanation:
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.