[c-nsp] Maximum number of OSPF instances in a VRF-lite environment

[Oliver Boehmer (oboehmer)]

McLean Pickett <> wrote on Wednesday, October 08, 2008 5:41 AM:

> I am working on a large campus design and I am on the fence between
> using a VRF-lite implementation (802.1q trunks carrying ospf
> instances between devices) and an MPLS VPN deployment.
> 
> If I only have a few VRF's then the VRF-lite implementation wouldn't
> be too overbearing and would require much less training for the
> support staff. However if the number of VRF's where to greatly
> increase then it seems like a full blown MPLS network is the better
> solution. 

right.. 
 
> Are there any Cisco guidelines or does anyone have any hands-on
> experience with the maximum number of VRF's\OSPF instances in a
> VRF-lite deployment? 

This is a typical "it depends" question, i.e. #of
routes/links/nodes/churn/etc. However we've tested > 100 OSPF instances
on NPE400/12000-GRP as PE-CE protocol in a rather simple topology
(requires the feature "OSPF Support for Unlimited Software VRFs per
Provider Edge (PE) Router"), so I would expect the number of OSPF
processes not being the limiting factor in your design.
I guess you want to explore MPLS-VPN when you need more than 10 or so
VRFs as provisioning will become very cumbersome with end-to-end
VRF-lite..

	oli