Going with confeds might not be a great idea in this situation. In very
large enterprise networks and various service provider networks this can
make sense both technically and administratively.
BGP confeds will take more administrative work since you will configure OSPF
in each confed (along with maintaining BGP in and amongst confeds),
redistribute into and out of bgp, have to deal with all the appropriate
filtering, and manually maintain metrics across BGP peers (if you like
taking the best cost paths)! And do you really want to punish yourself
(assuming you setup dampening) because you have an unreliable link
somewhere?
You'll obviously have to understand your networks characteristics and pick
the best solution. Done properly you can use various tricks like stub areas
to keep routing tables on all routers at reasonable sizes, minimize
convergence time, and make troubleshooting easier.
Kris,
> -----Original Message-----
> From: Jay Young [mailto:jay@net.ohio-state.edu]
> Sent: Friday, October 05, 2001 3:36 PM
> To: cisco-nsp@puck.nether.net
> Subject: Re: [nsp] OSPF area size
>
>
> Thanks for the replies. We don't really have anything that I would
> consider unstable. Mostly ATM or GigE over our own fiber on campus. We
> have a few T1's to remote sites but most of these don't run
> any routing
> protocol anyway as they only have one network behind them.
>
> Just out of curiosity is the reason you recommend confederated BGP so
> that the routes can be dampened across these unstable links?
>
> Jay
>
>
> "Robert E. Seastrom" wrote:
> >
> > "Ryan O'Connell" <ryan@complicity.co.uk> writes:
> >
> > > As long as the links in the area are relatively stable,
> this isn't a problem
> > > at all. If there are unstable links such as Satellite or
> Microwave links or
> > > long-distance WAN links prone to failure, it may make be
> worth moving
> > > them into a seperate area however.
> >
> > My $0.02: If you have a network big enough to profit from
> being broken
> > up (and I agree with Ryan's thoughts about the decision
> criteria), you
> > will be happier with confederated BGP (running OSPF within each
> > pseudo-AS) than you will with multiarea OSPF.
> >
> > ---Rob
>
> --
> Jay Young |Office of Information Technology
> Network Engineer |The Ohio State University
> Phone: (614) 292-7350 |1971 Neil Ave. (SE 480F)
> Fax: (614) 292-7081 |Columbus, OH 43210
>
>
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:50 EDT