Inter-VRF

[tiken]

Hello guys, hope all is well.

I need your help to understand something about VRF. In my lab, I want to simulate the interconnection of several sites with a datacenter using MPLS.

I have configured my

core mpls

, with IS-IS as the routing protocol.

Between my PE and CE I have OSPF "Sites are in the same area".

MP-BGP 

is activated and functional between my PE.

In this lab I have two VRFs, a

datacenter VRF and a stade VRF,

the problem is that I can't get the VRFs to communicate with each other. I've tried many things but it still doesn't work.

Since PE3 when I do a

sh ip route vrf datacenter

I can see the routes of the

vrf datacenter, and the same since PE1 when I do

sh ip route vrf stade 

I can see the routes of the

vrf stade.

Can you help me understand how routing between VRFs works?

[MHM Cisco World]

interface GigabitEthernet0/1
 ip vrf forwarding stade
 ip address 12.1.1.17 255.255.255.252
 ip ospf 3 area 1
 duplex auto
 speed auto
 media-type rj45

This interface not appear under stade in rib? That confuse me.

What appear is 192.168.10.0 which confuse me in first place.

[Harold Ritter · Accepted solution]

Hi @tiken ,

VRFs do not allow connectivity between themselves by default. You either need to use the import/export process to allow routes to be shared between the VRFs or have a CE router connected to both VRFs and that route between them. Here's a quick example of how the import/export process can be used to provide connectivity between VRF stade and datacenter.

PE1:

vrf stade doesn't not need to be configured locally

no ip vrf stade

ip vrf datacenter
rd 1:1
route-target export 1:1
route-target import 1:1
route-target import 1:3
!
PE2:

vrf stade doesn't not need to be configured locally

no ip vrf stade

ip vrf datacenter
rd 1:1
route-target export 1:1
route-target import 1:1
route-target import 1:3
!
PE3:

vrf datacenter doesn't not need to be configured locally

no ip vrf datacenter

ip vrf stade
rd 1:11
route-target export 1:3
route-target import 1:3
route-target import 1:1
!

Regards,

[tiken]

Hello,

Thank you for your reply, it works perfectly.

I understood my mistake.

[Harold Ritter]

You are very welcome @tiken and thanks for the feedback

[M02@rt37]

Hello @tiken,

In a multi-VRF environment, each VRF operates as a separate routing instance with its own routing table. By default, VRFs are isolated from each other, meaning the routes in one VRF are not visible or accessible to other VRFs. However, you can establish communication between VRFs using various mechanisms, such as route leaking or

VRF route importing/exporting

.

Follow example posted by @Harold Ritter.

In the datacenter VRF, you would export routes with a specific RT, and in the stade VRF, you would import routes with the same RT. 

[tiken]

Thank you all for your help