[c-nsp] Restrictions on topology when running OSPF with the customer inside VRF

[Junaid]

Hi,

I need some clarification as to what topology in which we can run OSPF
with our customer inside VRF. I ran OSPF on one PE-CE link in area 6.
I could only see in my VRF/OSPF table the intra-area routes and
external routes that were injected by the CE router via
redistribution. The CE router was also connected to other customer
routers via area 0 and other areas. In PE's VRF/OSPF routing table, I
could not see any inter-area route nor other external routes that
other customer routers were injecting via redistribution although I
could see them in my (PE router's) OSPF database. Funny thing is, when
I removed VRF configuration and configured OSPF with the customer in
the global routing table, I was able to see all routes getting
installed in the routing table. Consulting a book, I hit across the
following:

"When backbone areas are used within a VPN customer topology, the only
caveat to be aware
of is that any site configured to run an OSPF backbone area must be
attached directly with
the MPLS VPN Superbackbone, either through a direct link or a virtual
link. This is mandatory
because the PE routers always act as Area Border Routers (ABRs) and
need to be able to
exchange intra-area information with other ABR or backbone area routers."

Does this mean that the PE always need connectivity to Area 0? Is
there any way around? What am I missing?



Regards,

Junaid