MPLS in the campus Network?

Javier Solis jhazesnooty at
Fri Oct 21 17:02:24 UTC 2016

Our campus started off with L2 vlans spanning through the core, but we
migrated to routing in the core and moved our many spanning tree/broadcast
domains to the edge of buildings fronted by redundant routing with ecmp to
a redundant core utilizing ospf.

In a campus network the challenge becomes extending subnets across your
core. You may have a college that started in one building with their own
/24, but now have offices and labs in other buildings. They want to stay on
the same network, but that's not feasible with the routed core setup
without some other technology overlay. We end up not being able to extend
the L2 like we did in the past and today we modify router ACL's to allow
communications. If you already have hundreds of vlans spanned across the
network, it's hard to get a campus to migrate to the routed core. I think
this may be one of Marks challenge, correct me if I'm wrong please.

With that said, what are the best options to be able to cost effectively
scale without using vlans and maintaining a routed core? What technology
would someone suggest (mpls, vxlan,etc) to be the best possible solution?

Thank you to the participants in the discussion. I always enjoy reading
comments posted.


On Oct 21, 2016 11:46 AM, "Mark Tinka" <mark.tinka at> wrote:

> On 21/Oct/16 16:19, Marian Ďurkovič wrote:
> >
> > Much easier to setup, operate & maintain than MPLS and obviously much
> > lower cost. Based on 6-months production experience, my recommendation
> > would be to stay away from MPLS in the campus.
> I'd be curious to hear what MPLS-specific issues you faced in the 6
> months you had to operate such a network.
> Been running IP/MPLS Core, Edge and Access networks for over 15 years,
> and apart from bugs which affect any protocol or feature implementation,
> I can't say it has been a nightmare to operate to the point of not
> recommending it.
> I have far fewer words to say about STP, although - I'll admit - I've
> never run TRILL.
> Mark.

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