Inserting spbm transit area

[CordScott]

First some context is due. 

Looking at fabric deployment that has a large central area. I'd like to break it up in two by inserting a transit area. Problem I run into is that routes (ip shortcuts) don't make it from one one half of the now broken area into the other, which I'm sure is because of some loop prevention mechanism. 

Is there a way to do this? 

Can a vsp have more than one remote area? 

[Roger_Lapuh]

Loop prevention ensures that you don't do an area loop, but it won't affect redistribution of routes. I assume you have configured redistribution "multi-area ip redistribute unicast home-to-remote", have you?

[CordScott]

No ospf in this scenario. Some access sites already have their own areas, some do not. The problem is there is a large home area with DC and access sites in it. Moving these access sites to their down area is too disruptive (healthcare, high uptime requirement). 

Ideally I like a home area where no ip shorcuts are generated from it. The hang up is that this is a merged entity and there are overlapping ips that are very difficult to resolve. This is the real reason for the transient (backbone) area, just to have a filtering point beyond isis accept policies. The other option might be to use l3vn's to segment things and leak routes as needed. 

This is what I mean by transit area, its in this extreme video and other documentation

https://www.youtube.com/watch?v=6r7w20x-5p8

[WillyHe]

Hello,

It looks like you are discussing an OSPF setup? (transit AREA)

A VOSS/FabricEngine device can support a maximum of TWO AREA's in the FABRIC, HOME and REMOTE AREA.

We had also to split a customers large FABRIC only network and did it the following way.
The Multi-AREA setup is running as stable as the Single-AREA setup did before.

• One HOME AREA: for the DC sites (this was the existing AREA before migration).
• Four REMOTE AREA's:  for the ACCESS sites.

Traffic between ACCESS sites is forwarded via the HOME AREA between the Multi-AREA switches.
To avoid routing loops, it is never a good idea to interconnect two ACCESS AREA's.

regards
WillyHe