barring routing through same interface

[akin_lopez]

Hi all,

Is there a way i can tell my router not to route traffic out thesame interface it came from. (without access-list)

i.e hairpin routing

[omar_elmohri]

Hi,

well, you want that if you have a packet arrives from an interface you don't let it goback from the same interface, unless the routing table tells to forward it to this interface?? I think that by default, a router doen't forward packets to the same inferface that it comes.

Hope this can help,

Please rate if that help

Omar,

[gpulos]

you can use static routes to tell your router to send specific destinationTraffic to a specific interface.

also, with multiple paths you can configure cost routing by adding a cost to a static route. this would enable you to route traffic to one interface and in the case of that paths failure, use the other interface to route the traffic too.

ie: ip route 10.1.2.0 255.255.255.0 10.1.1.1

--- ip route 10.1.2.0 255.255.255.0 10.1.1.2 200

also, the mention above of a router 'not forwarding packets out an interface it receives', pertains to routingProtocols and split-horizon. where a learned route is not advertised/sent out an interface it was learned from. this is default behavior.

it is possible to have your router receive a packet on an interface and then send it back out that interface to its destination.

[akin_lopez]

Guys,

want i want to do is to tell the router not to route traffic back out the interface the traffic came from (i.e to drop it) even though the routing table says it should route it back that interface.

and i want to do this without access-list