MPLS-BGP L3 VPN Question

Answered Question
Feb 27th, 2007

Hi!

Can anyone tell me how I could see all the prefixes imported/exported by particular RT? Is there any command which will show me which prefixes are imported into the VRF as a result of 1 of the many configured RTs for that VRF?

Thanks.

Reg,

Niranjan

I have this problem too.
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Correct Answer by mheusinger about 9 years 7 months ago

Hi Niranjan,

you can define an extended community list and match on that. Example:

R1(config)#ip extcommunity-list expanded myRTlist permit 65000:1

R1#show bgp vpnv4 unicast [all|rd RD| vrf VRFNAME] extcommunity-list myRTlist

OR

R1#show ip bgp vpnv4 all extcommunity-list myRTlist

This will filter based on RT, which is especially helpful on route-reflectors, where no VRFs are configured.

Hope this helps!

Regards, Martin

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mikedavi1 Tue, 02/27/2007 - 00:35

Imported into vrf xxx:

show ip bgp vpn vrf xxx

Exported to a neighbor 1.1.1.1:

show ip bgp vpn all neighbors 1.1.1.1 advertised-routes

HTH,

Mike

n.nandrekar Tue, 02/27/2007 - 02:33

Thanks Mike!

These show commands seem fine but they will show all the routes in the VRF table (imported routes) or all routes exported to a neighbour( second command)

What I was looking for is how to see the routes imported/exported by a perticular RT.

eg. I might have 3 different import RTs and also might have different export RTs for the same VRF.

The commands that you suggested would give me the cumulative result. Is there some command using which I could see exactly which routes are imported/exported by a particular RT from a set of RTs that I have configured for the same VRF.

Thanks.

reg, Niranjan

Correct Answer
mheusinger Tue, 02/27/2007 - 04:31

Hi Niranjan,

you can define an extended community list and match on that. Example:

R1(config)#ip extcommunity-list expanded myRTlist permit 65000:1

R1#show bgp vpnv4 unicast [all|rd RD| vrf VRFNAME] extcommunity-list myRTlist

OR

R1#show ip bgp vpnv4 all extcommunity-list myRTlist

This will filter based on RT, which is especially helpful on route-reflectors, where no VRFs are configured.

Hope this helps!

Regards, Martin

mikedavi1 Tue, 02/27/2007 - 10:14

Sorry I misunderstood what you were looking for. Looks like Martin got you hooked up. He's quite good at that!

I'm partial to the cumulative view in that I can verify that I don't any unwanted routes caused by faulty policy. Not such a big deal when you are just doing RT import/export, but things can get hairy when you are using route-maps on vpnv4 peers or in the vrf.

Anyway, I'm glad you got the answer you needed.

Mike

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