Re: Running BGP4 on a Core Router

["Chris" <chris () bgpconsulting com>]

The atm part is only the layer two core C&W and UUnet, both have ip on all
core routers taking full bgp routes. Much like sprint has a POS core, but
they still run ip over it. You have to have some kind of layer 2 core to run
ip over so if you think about it every one has some kind of overlay model.
          Chris
----- Original Message -----
From: "Dmitri Krioukov" <dima () krioukov net>
To: "Bora Akyol" <akyol () akyol org>
Cc: "nanog" <nanog () merit edu>
Sent: Tuesday, July 11, 2000 9:54 PM
Subject: RE: Running BGP4 on a Core Router


> we can even imagine some core that is
> not ip core but, say, atm core and all
> lsrs are atm-lsrs.
>
> actually some providers (like c&w)
> have exactly this no ip core, overlay
> model. it's far from being the best one.
> --
> dima.
>
> > -----Original Message-----
> > From: owner-nanog () merit edu [mailto:owner-nanog () merit edu]On Behalf Of
> > Bora Akyol
> > Sent: Monday, July 10, 2000 12:10 AM
> > To: nanog
> > Subject: Re: Running BGP4 on a Core Router
> >
> >
> >
> > Even with MPLS, you need to run some sort of a routing protocol.
> >
> > ISIS or OSPF with TE extensions would do.
> >
> > One can also use BGP with MPLS Label extensions as well. By the way, how
> > does this work with route reflectors?
> >
> >
> > Bora
> >
> >
> > ----- Original Message -----
> > From: "Jesper Skriver" <jesper () skriver dk>
> > To: "HANSEN CHAN" <hansen.chan () alcatel com>
> > Cc: <nanog () merit edu>
> > Sent: Sunday, July 09, 2000 8:20 PM
> > Subject: Re: Running BGP4 on a Core Router
> >
> >
> > > On Sun, Jul 09, 2000 at 07:49:37PM -0400, HANSEN CHAN wrote:
> > > > Hi folks,
> > > >
> > > > I was hearing that typically BGP4 is run on all routers inside a
POP,
> > > > including access routers connecting to customers, border routers
> > > > connecting other ISPs and core routers connecting to other POPs in
the
> > > > same network.
> > > >
> > > > I can understand why BGP4 is run on access and border routers. But
> > > > running BGP4 on core routers is beyond my understanding. I thought
you
> > > > don't need to run BGP4 on core routers which are considered to be
> > > > interior nodes.
> > > >
> > > > Can someone shed some light on what is the benefit of running BGP4
on
> > > > the core routers?
> > >
> > > If these routers run "normal" ip routing you have to, as each router
> > > does a lookup of the destination ip address of each packet, and
forward
> > > it accordingly.
> > >
> > > If you run MPLS, you don't have to, as it uses labels to get to the
> > > next-hop router.
> > >
> > > /Jesper
> > >
> > > --
> > > Jesper Skriver, jesper(at)skriver(dot)dk  -  CCIE #5456
> > > Work:    Network manager @ AS3292 (Tele Danmark DataNetworks)
> > > Private: Geek            @ AS2109 (A much smaller network ;-)
> > >
> > > One Unix to rule them all, One Resolver to find them,
> > > One IP to bring them all and in the zone to bind them.