Route leaks between VRFs

[zeeshanbasit25789]

PE1 has two vrfs configured CE1A and CE2A.

Both CE1A (155.1.111.11/24) and CE2A (155.1.112.12/24) are advertising their loopback addresses.

I am trying to leak the loopback of CE2A (150.1.112.12/32)  into CE1A without using the import route-target.

I have created the following prefix list and the route map.

ip prefix-list CE2A-LO seq 5 permit 150.1.112.12/32

route-map EXPORT_CE2A permit 10
match ip address prefix-list CE2A-LO
set extcommunity rt 65100:100 (i have tried with additive as well)
route-map EXPORT_CE2A permit 20

I have tried importing the route-map in the VRF and I have also tried to apply it though BGP under the VRF but nothing works.

[MHM Cisco World]

Without RT you can not

RT export/import all prefix then you can filter it by route-map

MHM

[zeeshanbasit25789]

@MHM Cisco World 

Yes I tried that option but I was thinking if it is possible to selectively advertise it. So that is the only way possible importing all and then filtering it out? Would you say that it is the best practice adoptive in the production envrionment as well?

[MHM Cisco World]

So that is the only way possible importing all and then filtering it out? Correct 

MHM

[MHM Cisco World]

Would you say that it is the best practice adoptive in the production envrionment as well? I Dont get this Q' can you elaborate 

But

Two CE connect to same PE and need route leaking is rare.

MHM

[MHM Cisco World]

And again without using RT (route-target import or export) prefix not leaking between VRF in bgp.

Any other solution not work.

MHM

[Joshqun Ismayilov · Accepted solution]

Good day @zeeshanbasit25789  from your topology- you can use an import map that selectively imports prefixes into CE1A.

#ip prefix-list CE2A-LO seq 5 permit 150.1.112.12/32

#route-map IMPORT_TO_CE1A permit 10
#match ip address prefix-list CE2A-LO
#route-map IMPORT_TO_CE1A permit 20

and under VRF CE1A:

#vrf definition CE1A
#rd 65100:1
#route-target export 65100:1
#import map IMPORT_TO_CE1A

You can try to test it .

Thanks !

[zeeshanbasit25789]

Hi @Joshqun Ismayilov 

I have tried that, it didn't work.

[Harold Ritter]

Hi @zeeshanbasit25789 ,

What @Joshqun Ismayilov recommended is the right way to do it, but it needs to be used in conjonction with the route-target import/export.

vrf definition CE1A

address-family ipv4

route-target import 1:2

route-target export 1:1

import map IMPORT_TO_CE1A

!

vrf definition CE2A

address-family ipv4

route-target import 1:1

route-target export 1:2

import map IMPORT_TO_CE2A

[M02@rt37]

Hello @zeeshanbasit25789 

See EVN 'easy-virtual-network'

On vrf definition/address-family-ipv4 see route-replicate command

On each VRF ...

--

https://lostintransit.se/2021/09/17/route-replication-the-easy-way/

https://community.cisco.com/t5/documents-de-routage-et-commutation/easy-virtual-network-evn/ta-p/5276048

[paul driver · Accepted solution]

Hello
the vrf import/export map feature is for advertising-(leaking) or filtering between VRF ribs or the GRT or both with route-targets import/export being required.

The suggestion by M02@rt37 is a feature i’ve personally only have tested in a lab environment - using those vnet trunks and my understanding it needs to run on a minimum ios-xe platform -maybe other could confirm this?

[M02@rt37]

Hello @paul driver 

EVN is supported on IOS version 15.2(4)S3 or later or IOS XE.