nanog mailing list archives

RE: bad idea?


From: "Richard A. Steenbergen" <ras () e-gerbil net>
Date: Wed, 5 Jul 2000 20:26:20 -0400 (EDT)


On Wed, 5 Jul 2000, Dmitri Krioukov wrote:


the major disadvantage of the foundry (bgp)
solution is longer prefix injection.

the major problem with the dns-based solutions is
that they're not topology-aware (-> suboptimal
routing). attempts to make dns smart lead to
rather awkward reverse pinging configurations
and proprietary protocols running between load
balancers. (there was also rfc2052 by paul vixie
but it required modification of dns clients.)

I don't think anyone sane would advocate a reverse pinging setup, but
rather returning a DNS answer based on which DNS server you hit, and you
hit the DNS server thats "closest" to you. I guess it depends what you
value, short web traffic and instantanious failover regardless of the
disruption of existing connections due to a route flap or metric change
(remember this could be the fault of ANYONE's network, not necessarily
yours), or guarenteed connections with possible non-instantanious
failover. It also depends on the density of your server farms (one on the
east coast, one on the west coast, it would take a fair amount of problems
for the routes of the "majority" of people on either coast to change to
the other). This is grossly generalized load balancing at its finest, take
from it what you will.

-- 
Richard A Steenbergen <ras () e-gerbil net>   http://www.e-gerbil.net/humble
PGP Key ID: 0x138EA177  (67 29 D7 BC E8 18 3E DA  B2 46 B3 D8 14 36 FE B6)




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