[NANOG] OSPF minutia, and, technote publication venues

Mon May 5 17:18:56 UTC 2008

On Mon, May 5, 2008 at 10:07 AM, Paul Vixie <vixie at isc.org> wrote:
> 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 that route be withdrawn.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.

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
>
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-- 
Chris Grundemann
www.linkedin.com/in/cgrundemann