The Branch Gateway enables you to configure a static route as a permanent route. Configuring this option prevents the static route from becoming inactive when the underlying Layer 2 interface is down. This prevents routing table updates from being sent each time an interface goes up or down when there is a fluctuating Layer 2 interface on the static route. Configure the permanent option using the ip route command.

For example, the command ip route 193.168.10.0 24 FastEthernet 10/2 permanent creates a permanent static route to the network 193.168.10.0 24 via the FastEthernet 10/2 interface.

The command ip route 132.55.0.0 255.255.0.0 132.55.4.45 3 high creates a high static route to the network 132.55.0.0/255.255.0.0 using next-hop ip address 132.55.4.45 and with cost 3.

Permanent static routes should not be configured over Layer 2 interfaces that participate in a Primary-Backup pair.

For more information on Backup interfaces, see Backup interfaces.