BigIron RX Series Configuration Guide 57153-1001986-01Trunk formation 22Setting the output interface to the null interfaceThe following commands configure a PBR to send all traffic from 192.168.1.204/32 to the nullinterface, thus dropping the traffic instead of forwarding it.BigIron RX(config)# access-list 56 permit 209.168.1.204 0.0.0.0The following commands configure an entry in a route map called “file-13”. The first entry (permit56) matches on the IP address information in ACL 56 above. For IP traffic from the host209.168.1.204/32, this route map entry sends the traffic to the null interface instead offorwarding it, thus sparing the rest of the network the unwanted traffic.BigIron RX(config)# route-map file-13 permit 56BigIron RX(config-routemap file-13)# match ip address 56BigIron RX(config-routemap file-13)# set interface null0BigIron RX(config-routemap file-13)# exitThe following command enables PBR by globally applying the route map to all interfaces.BigIron RX(config)# ip policy route-map file-13Alternatively, you can enable the PBR on specific interfaces, as shown in the following example.The commands in this example configure IP addresses in the source subnet identified in ACL 56,then apply route map file-13 to the interface.BigIron RX(config)# interface ethernet 3/11BigIron RX(config-if-e10000-3/11)# ip address 192.168.1.204/32BigIron RX(config-if-e10000-3/11)# ip policy route-map file-13Trunk formationWhen a trunk is formed, the PBR policy on the primary port applies to all the secondary ports. If adifferent PBR policy exists on a secondary port at a time of a trunk formation, that policy isoverridden by the PBR policy on the primary port. If the primary port does not have a PBR policy,then the secondary ports will not have any PBR policy. When a trunk is removed, reload the deviceto restore any PBR policies that were originally configured on the secondary ports.
