Do we need two VRF interfaces in one router?

[wfqk]

Hi One traffic needs to go through a router from one vrf interface to the second interface. Do you think if the second interface has to be vrf interface in order to allow the traffic go out? Thank you

[Philip D'Ath]

You don't provide enough information to help very easily.

If the second interface isn't used for anything else, then yes, you can just place both interfaces in the same vrf.

[wfqk]

Thank you for your reply. 

In anther word, the traffic must goes into the router from e1/1, which is vrf ABC. And there is only another interface e1/2 in the same router for the traffic to go out. the e1/2 has to be vrf interface and it has to be vrf ABC, right?

[Philip D'Ath]

Ideally yes, but you can also do inter-vrf routing (with imports and exports), if you like a lot pf pain.

[wfqk]

the traffic has to go out through e1/2. If the e1/2 is not vrf interface, the traffic would be blocked at e1/2, right? I would like you to further confirm it : ) thank you

[Philip D'Ath · Accepted solution]

If eth1/2 does not have an explicit vrf configured then it will be a member of the global vrf.  If you have no routes being imported/exported between the global vrf and vrf ABC then no traffic will flow between the two interfaces as they are in separate vrfs.

[wfqk]

Right! Thank you