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MPLS/VPN route leak configuration between VRFs

Hi,

I'm struggling with a small problem.

let say we have 3 routers - R1,R2 and RR.

we have 2 VRF:

CustA - RD100:1

MGMT - RD:100:100

RR is a router reflector

the topology looks like:

MPLS-VPN-leak.jpg

I'm trying to export a cirtain routes from CustA to MGMT with help of following route-maps on router RR

ip access-list standard MGMT

permit 192.168.100.0 0.0.0.255

!

route-map MGMT  permit 10

match ip address MGMT

set extcommunity rt  100:999 additive

for the test purpose a loopback interface was configured on R1  in CustA VRF with IP from 192.168.100.0/24 subnetz.

All routing information are correctly distributed over all routers,  but export  doesn't work - the IP from 192.168.100.0/24 doesn't get the additionla RT 100:999.

If I configure the "export-map" in VRF configuration on R1 then the export works perfectly - 192.168.100.0/24 gets additional RT 100:999 and it's then imported by the router RR in VRF MGMT.

But, as far as I understand the export should work exactly in the same way if I do it only on RR router, shouldn't it ? I mean if take a real life network - we don't want to configure that export-map on all PE routers for all VRF, it should be enough if we do it centrally - on the router-reflectors.

What can be wrong with my configuration?

3 Replies 3

Hi again,

just to clear the things:

Is it true that "export-map" works only for prefixes which are inserted in the VRF localy on the router?  I coudn't find any conformation or rejecting of this statement.

Hi Konstantin,

that is true, RRs do not actually export the routes, rather reflect them and hence this feature is not applicable on those(unless one has a VRF with the interfaces being advertised on a RR). I would go for a route-map under VPNv4 address-family to achieve what you need.

On a side note, this might be worth looking into -

http://www.cisco.com/en/US/docs/ios/iproute_bgp/configuration/guide/irg_rt_filter.pdf

http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_bgp/configuration/xe-3s/irg-rt-filter.html#GUID-C3CF0BA1-4265-4939-BE9A-D00588553A3E

Hope that will help,

Ivan.

Hi Ivan,

thank you for the update and links, I'll study them.

Do you mean the problem in my configuration could be the route-reflector topology? I'll try to test without RR but anyway it will be not useable in production network.

I've founf this simple topology example

http://rekrowten.wordpress.com/2011/12/12/route-leaking-between-vrfs-by-using-export-maps/

and it looks like the export is working fine in this example and exports the routes on the remote router, but that remote router does a redistribution from OSPF into BGP, may be this is the trick.

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