Export route-map appears to not be working.

[Daniel Smith]

I have multiple vrf's ona router with one being the source of leaked routes and advertising into the others. For a lab build, I just did two vrf's and was able to recreate the issue. Given some routes in the vrf MSTUNNEL:

B 10.0.253.187/32 [20/0] via 10.97.1.35, 00:05:17
B 10.0.253.188/32 [20/0] via 10.97.1.35, 00:05:17

and with these configurations:

ip vrf MSTUNNEL
rd 4280000174:10200
export map MSTUNNEL-NETWORKS-EXPORT
route-target export 10200:10001
route-target import 10200:20001
!
ip vrf ATT
import map MSTUNNEL-NETWORKS-IMPORT
route-target export 10200:20001
route-target import 10200:10001

to demonstrate this, I made the MSTUNNEL-NETWORKS-EXPORT into a deny process:

route-map MSTUNNEL-NETWORKS-EXPORT, deny, sequence 1

This is certainly not the intended design, but demonstrates what I am confused by. The ATT vrf still has IP routes from the MSTUNNEL vrf:

R34-ACCESS5#show ip route vrf ATT

B 10.0.253.187/32 [20/0] via 10.97.1.35 (MSTUNNEL), 00:08:14
B 10.0.253.188/32 [20/0] via 10.97.1.35 (MSTUNNEL), 00:08:14

So the two routes from the MSTUNNEL vrf, are in the ATT vrf, even though the export map is essentially a 'deny all'.

The route-map MSTUNNEL-NETWORKS-IMPORT allows the networks above and works as expected when I tweak it. However, I believe the EXPORT route-map should be denying all routes......

[Flavio Miranda]

@Daniel Smith 

where did you apply the route-map and how?

[Daniel Smith]

The route-maps are configured under the vrf definitions above.

[MHM Cisco World · Accepted solution]

https://www.trueneutral.eu/2014/ios-vrf-export.html

the answer to your Q

MHM

[Daniel Smith]

The link provided above provides exactly the information I needed and showed how to use export maps. Using just an export map under one VRF (removed route target export value) and an import route-target #####:##### on the destination VRF, it is working great. 

I have not tried it in lab yet, but do you think an import map, matching on ExtCommunity, could replace the import route-target #####:##### on the destination VRF?

[filopeter · Accepted solution]

Export map can only be used for adding different/additional route-target to BGP update.  No other set/filtering operation can be performed by that route map. If you want to filter prefixes, you have to use import map.