From: Chris Grundemann (no email)
Date: Mon May 05 2008 - 13:18:56 EDT
On Mon, May 5, 2008 at 10:07 AM, Paul Vixie <> wrote:
> (Steve Gibbard) writes:
>
> > > ... if each anycast cluster is really several servers, each using OSPF
> > > ECMP, then you can lose a server and still have that cluster advertising
> > > the route upstream, and only when you lose all servers in a cluster will
> > > that route be withdrawn.
> >
> > This is getting into minutia, but using multipath BGP will also accomplish
> > this without having to get the route from OSPF to BGP. This simplifies
> > things a bit, and makes it safer to have the servers and routers under
> > independent control.
>
> i think the minutia is good, especially after a long weekend of layer 9
> threads. my limited understanding of multipath bgp is that it's a global
> config knob for routers, not a per peer knob, and that it has disasterous
> consequences if the router is also carrying a full table and has many peers.
I am not sure what routers specifically are being discussed here, but
in JunOS you can enable multipath on a global, group or single
neighbor level, possibly eliminating your concern...
> also, in OSPF, ECMP is not optional, even though most BSD-based software
> routers don't implement it yet (since multipath routing is very new.) so,
> we have been using OSPF for this, it just works out better. i dearly do
> wish that something like a "service advertisement protocol" existed, that
> did what OSPF ECMP did, without a router operator effectively giving every
> customer the ability to inject other customer routes, or default routes.
> in that sense, i agree with your "safer... independent control" assertion.
>
> > But yes, Joe's ISC TechNote is an excellent document, and was a big help
> > in figuring out how to set this up a few years ago.
>
> and now for something completely different -- where in the interpipes could
> a document like that have been published, vs. ISC's web site? the amount
> of red tape and delay involved in Usenix or IETF or IEEE or ACM are vastly
> more than most smart ops people are willing to put in. where is the light /
> middle weight class, or is every organization or person who wants to publish
> this kind of thing going to continue to have the exclusive and bad choice of
> "blog it, or write an article for ;login:/ACM-Queue/Circle-ID, or write an
> academic paper and wait ten months"? isn't this a job for... NANOG?
> --
> Paul Vixie
>
> _______________________________________________
> NANOG mailing list
>
> http://mailman.nanog.org/mailman/listinfo/nanog
>
-- Chris Grundemann www.linkedin.com/in/cgrundemann _______________________________________________ NANOG mailing list http://mailman.nanog.org/mailman/listinfo/nanog
|
|
|