Configuring unicast Reverse Path Forwarding modes

You can configure the various uRPF modes on a Layer 3 VE or physical interface.
You must enable uRPF forwarding globally before you enable the required forwarding modes.
  1. Enter global configuration mode. 
    device# configure terminal
  2. Enter interface configuration mode. 
    device(config)# interface ethernet 1/1/9
  3. Enter the rpf-mode command followed by the required mode (strict or loose) you want to configure on the device. You can optionally use the exclude default route check (urpf-exclude-default) on the physical interface.

The following example shows the uRPF strict mode enabled. 

device# interface ethernet 1/1/9
device(interface ethernet 1/1/9)# rpf-mode strict
Parent topic: Unicast Reverse Path Forwarding