Chapter 2 Advanced Routing for FortiOS 5.0 : Advanced Static Routing : Static routing tips : Configure as much security as possible
  
Configure as much security as possible
Securing your network through static routing methods is a good low level method to defend both your important information and your network bandwidth.
Implement NAT to obscure your IP address is an excellent first step.
Implement black hole routing to hide which IP addresses are in use or not on your local network.
Configure and use access control list (ACL) to help ensure you know only valid users are using the network.
All three features limit access to the people who should be using your network, and obscure your network information from the outside world and potential hackers.