[NANOG] OSPF minutia, and, technote publication venues

Mon May 5 16:07:03 UTC 2008

scg at gibbard.org (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 that route be withdrawn.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.
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