On Mon, May 5, 2008 at 10:07 AM, Paul Vixie <[EMAIL PROTECTED]> wrote: > [EMAIL PROTECTED] (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 that route be withdrawn.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 > NANOG@nanog.org > http://mailman.nanog.org/mailman/listinfo/nanog > -- Chris Grundemann www.linkedin.com/in/cgrundemann _______________________________________________ NANOG mailing list NANOG@nanog.org http://mailman.nanog.org/mailman/listinfo/nanog
