Injecting Global default Routes into a MPLS VPN

[subhashe]

Hi,

I have a PE router running MPBGP which receives two default routes to the internet through an IPV4 BGP session. I need to import these routes in to a VRF and export them to different customer VRFs so that these VRFs are able to access Internet.

I have used the feature called "BGP Support for IP Prefix Import from Global Table into a VRF Table" (URL:http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_feature_guide09186a00803b8db9.html#wp1063870)

and imported these routes into a VRF.

The issue is these routes are not propagated to any of the other PE routers which has customer VRFs configured.

Has anybody tried this or a similar method to inject a dynamic default route into a MPLS VPN.

Any suggestions would be highly appreciated.

Thanks

Subhash

[attrgautam]

That is right, if you do ipv4 import into VRF, then you cannot export to other vpn's. It is a limitation of the feature. How about adding a static global route ie leaking the default route into the cloud. All packets will come to the PE and then look into the ipv4 routing table and take the default out.

[subhashe]

Hi,

Thanks for the reply. I am receiving two default routes from my two Internet Gateways via BGP. My plan is to failover traffic to the second gateway if the first gateway or it's internet link is down.

[mheusinger]

Hi Subhash,

is there anything preventing you from terminating your internet BGP sessions in a VRF? Then everything should go smoothly, i.e. standard VRF import/export.

So possibility A) create a VRF Internet, move bgp neighbor commands there and use filters preventing anything but the default route, then use route targets to distribute the default route into other VRFs.

Possibility B) use static routing with packet leaking. Could look like this:

ip route vrf Internet 0.0.0.0 0.0.0.0 global

ip route vrf Internet 0.0.0.0 0.0.0.0 global 250

ip route Serial0/0 !assuming this is where the customer router connects.

Note: the BGP peer IP does not have to be directly connected! There has to be a LDP label for it though. so include your BGP peers network into your IGP and the backup will work, when you loose the link to the peer.

Hope this helps! Please rate all posts.

Regards, Martin

[subhashe]

Hi Martin,

I think the Option A is best Suited to my scenario.

Thanks for your response.