Stopping route aggregation to MPLS network

[Kandarp Patel]

Hello There,

We are trying to utilize Aggregate route summary feature on our MPLS network with customer connection and looking for advise on it.

There are multiple customer connections from multiple MPLS edge routers on same VRF. On one of the customer connection, we are trying to advertise aggregate routes only due to number of prefix limitation, but while doing this, Null routes are created (as expected and understood) and advertised to all MPLS edge routers via iBGP on that vrf and ultimately forwarded to other customer connections on same vrf which is not required.

We see one way is to put route-policy with prefix-set to block advertisement on customer connections that do not require these Null routes being advertised to, but is there any other efficient way to avoid setting up prefix-sets and route-policies on all edge router with customer connections?

Thank you

[MHM Cisco World]

If you use aggreate command then there is keyword summary-only

This make router only advertise summary not all prefix.

[Kandarp Patel]

Thanks for the response @MHM Cisco World. We already have summary-only as part of configuration, and may be I didn't get my question right. But as shown in below diagram, We have aggregate with summary-only configuration done on PE-1 router where CE1 customer is SiteA is connected to. We want 10.0.0.0/8 to be advertised to Site-A but not to Site-B, Sire-C or Site-D that are connected to other PE routers. Trying to find most efficient way to block this advertisement. Thank you!

[MHM Cisco World]

Export-map match aggreate and set rt 

Then import-map this rt only in site you want.

[Kandarp Patel]

Thank @MHM Cisco World . Any sample configuration or document related to Export-map to match aggregate and set rt?

[MHM Cisco World · Accepted solution]

VRF Export Maps - PacketLife.net

this can help you

[Kandarp Patel · Accepted solution]

Thank you @MHM Cisco World . We were able to get this going. 

Below is the configuration sample we applied.

##PE-1 (Where aggregate-route is configured)##

prefix-set Aggregate_Prefix
10.0.0.0/8

route-policy Export-Map-Test
 if destination in Aggregate_Prefix then
  set extcommunity rt (65000:2)
 else
  pass
 end-policy

vrf Test

 address-family ipv4 unicast
  import route-target
   65000:1
   !
  export route-policy Export-Map-Test
  export route-target
   65000:1
   65000:2

##PE-2 and PE-3 (Where aggregate-routes are not required)##

vrf Test

 address-family ipv4 unicast
  import route-target
   65000:1
   !
  export route-target
   65000:1
 

##PE-4 (Where aggregate-routes are required)##

vrf Test

 address-family ipv4 unicast
  import route-target
   65000:1

   65000:2
   !
  export route-target
   65000:1