[c-nsp] OSPF design

[Oliver Boehmer (oboehmer)]

> So my question is should we separate the network into different OSPF
areas
> as Cisco recommendation or should we keep all routers in an OSPF area
0?
> Note that we intend to provide MPLS L2VPN, L3VPN on this network; we
can
> only use OSPF, ISIS is not an option.

the recommendation of no more than 50 nodes/area is >10 years old, and
given today's routers' CPU performance and the fact that your OSPF is
likely extremely slim (only links and loopbacks), with all customer
prefix in BGP/vpnv4, you can and should put all routers into a single
OSPF area 0.. makes things simpler.. If you need to scale the access
massively, you can still add non-backbone areas to the edge later..

	oli