Chapter 2 Advanced Routing for FortiOS 5.0 : Advanced Static Routing : Static routing example : Configure FortiGate unit : Configure networking information
  
Configure networking information
Networking information includes the gateway, and DNS servers. Your FortiGate unit requires a connection to the Internet for antivirus and other periodic updates.
To configure networking information - web-based manager
1. Go to System > Network > Options.
2. Enter the primary and secondary DNS addresses.
3. Select Apply.
To configure networking information - CLI
config system global
set dns_1 172.11.22.33
set dns_2 172.11.22.34
end