MPLS dynamic route leaking

cparker72 · ‎04-04-2008

Hello,

I am looking for a way to leak routes from MPLS vpns into the global routing table.

I am familiar with how this is done using static routes, but I have run into a situation where using static routes causes a problem when there is a network outage.

I am using a frame encapsulation on redundant OC-3 that carry the MPLS vpns on various DLCIs. The frame is set up with no keepalives (it isnt true frame, just used as a way to subdivide the OC3). So if the one of the OC3s go down the POS interfaces still show up/up and the static routes stay in the table.

I need to find a way to leak the routes from the vpns into the global table that doesnt use a static route so when the routes leave the vrf's table in the vpn due to a circuit outage, the routes leaked to the global table do not persist due to the fact they are tied to an interface that never goes down.

shivlu jain · ‎04-05-2008

ip route vrf TEST x.x.x.x y.y.y.y next-hop global

regards

shivlu

pcarvill · ‎04-06-2008

Perhaps you could use some form of object tracking?

http://www.cisco.com/en/US/docs/ios/12_4/dial/configuration/guide/hdbackup.html#wp1057186

I have not tested this, but maybe you could track your interfaces and when they go down the static route shoud disapear. Is this what you want to achieve?

Paul

cparker72 · ‎04-06-2008

Paul,

That's a good idea using IP SLA, I might use that.

Currently my thinking is to leak the routes from the vrf into the global table at a P router that can see the routes coming from both the PE with the active link and the PE with the redundant link. When there is a failure on the active PE's link to the CE, those routes will leave the vrf and the P router will only see the backup routes.

I'm going to try this out by putting a loopback interface on a P router and putting that loopback in the vrf. Then I will point my statics to that loopback.