[c-nsp] IPv6 PE-CE

[Benny Amorsen]

Saku Ytti <saku at ytti.fi> writes:

> It shouldn't be argued this direction, BGP needs no justification, IGP
> does.

Fair enough.

> We did this decade ago, no one has looked back. Configuring BGP in certain
> platforms can be 0 touch on PE. Like if you use 'allow CIDR' in JunOS or 'bgp
> listen range CDIR peer-group X' in JunOS you don't even need to touch PE
> when adding CE.

I suppose I could dynamically generate a neighbor allow when a new
interface is provisioned on the PE. You still need to touch the CE
though, whereas with OSPF you basically just need to enable it on the
interface.

You must be usíng the interface addresses for the BGP peering endpoints,
since you would need an IGP to reach any loopbacks, and we are trying to
avoid running an IGP? I cannot get away with using the same BGP neighbor
address for all CE's.

> In JunOS you can further reduce config cruft by using apply-group to fill
> in all stuff like import/export maps, asn, as-override etc, so those would
> only appear in single place.

Nice.

>> OSPF may be expensive in theory, but in practice it performs well.
>
> RIP is the real scale beast :) If you truly need to run thousands of
> sessions. I know someone doing RIP to the server at TOR, where RIP was only
> scalable solution.

It is indeed, I have considered that too.


/Benny