MPLS VPNs or not?

Tue Aug 7 14:16:18 UTC 2001

On Tue, Aug 07, 2001 at 09:03:53AM -0500, Andy Walden wrote:
> On Tue, 7 Aug 2001, Christian Kuhtz wrote:
> >
> > I think it's pretty well known that the point you mention is FUD.  Besides,
> > it's not really intended to be 'multiple tables' with multiple instances of
> > routing processes.. it's an indexed table run by the same routing process.
> 
> Logic says that not seeing the routes at all, a la layer-2 tunnels, is
> going to scale *better* then having your routers deal with them at all.

I really wanted to reply... "Logic says you need to check the facts before 
posting such nonsense." .. but that would be a flame.  Let's try this instead:

In an RFC2547(bis) MPLS-VPN, the edge doesn't neccessarily need to see all the 
routes at all.  All the PE does need to know is enough for the two CE's to 
communicate with each other.  This can be a static route, this can be a summary
route.  So, if you get another, say 3000 routes for 1000 customers, this is
really going to be that much of a scaling problem?  In fact, if your customers
build BGP sessions etc between their CE's, the routes carried by the PE's are
very skinny.  

So, you're going to try to tell us next that n^2 tunnels scale better and are
less of an operational nightmare at scale than the connectivity provided 
inside of an MPLS-VPN? 

Have you ever actually used the code yourself?

-- 
Christian Kuhtz <ck at arch.bellsouth.net> -wk, <ck at gnu.org> -hm
Sr. Architect, Engineering & Architecture, BellSouth.net, Atlanta, GA, U.S.
"I speak for myself only."