Add fabric extend to current mesh

[bfaltys]

This will build on something I posted about a while back, but the situation is this:

-we have a fabric built across the city with our own owned fiber

-we are getting additional, redundant links from an ISP

-we want to use the ISP links to add to our fabric

-we have 2 test sites up. One is only connected to the ISP and the fabric extend is working. the other site is connected to the ISP and our original fabric. In the second case, the link over the ISP shows “INIT” for the IS-IS adjacency. Is it possible to have full adjacency over the ISP and our original fabric at the same time?

-For the fabric extend, I am using brouter ports and I have loopback IP as tunnel source & destination. Both of these are running OSPF so that I don’t have to build a bunch of static routes going forward. I also added OSPF redistribution into IS-IS.

I can add configs/diagrams, but wanted to throw out some facts and the question.

[Roger_Lapuh]

Yes, you can have Physical and Logical NNIs in your setup. This is perfectly fine. 

What I assume is happening in your setup is that your underlay FE routes are learnt through an NNI. This has to be avoided as we cannot run FE over MACinMAC.

You can either:

1. use a separate (non-IS-IS)VRF for your underlay as you have done. This will ensure FE underlay routes are never learnt through IS-IS.
2. if you use the same routing table for your FE underlay as well as your IS-IS routed traffic, then you will have to configure a route policy ensuring that your FE underlay routes are not learnt through IS-IS.

Makes sense?

Roger

[bfaltys]

Another update: This works if I use a separate VRF for the links over the ISP. Not sure on the technical details of why this works.

[bfaltys]

One update, I built this out in a lab. Without redistributing OSPF into ISIS...If I remove the direct link the primary adjacency goes down and the fabric extend adjacency comes up. So, what can I do to have both adjacencies at the same time?