Chapter 7 Firewall : Security policies : Firewall policies : Firewall policy parameters : Destination Address
  
Destination Address
In the same way that the source address may need to be limited, the destination address can be used as a traffic filter. When the traffic is destined for internal resources the specific address of the resourece can be defined to better protect the other resources on the network. One of the specialized destination address options is to use a Virtual IP address. The destination address doesn’t need to be interal you can define policies that are only for connecting to specific addresses on the Internet.