[40899] in North American Network Operators' Group
Re: multi-homing fixes
daemon@ATHENA.MIT.EDU (Leo Bicknell)
Fri Aug 24 20:57:47 2001
Date: Fri, 24 Aug 2001 20:57:14 -0400
From: Leo Bicknell <bicknell@ufp.org>
To: nanog@merit.edu
Message-ID: <20010824205714.A62564@ussenterprise.ufp.org>
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nanog@merit.edu
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In-Reply-To: <E15aRD9-000OpY-00@rip.psg.com>; from randy@psg.com on Fri, Aug 24, 2001 at 05:22:03PM -0700
Errors-To: owner-nanog-outgoing@merit.edu
On Fri, Aug 24, 2001 at 05:22:03PM -0700, Randy Bush wrote:
> haven't thought about it for a while, but ... probably rethink my
> requirements a bit.
Let me give you the first two requirements:
1) Your investors won't give you money unless you have 'redundant'
connectivity for your e-whatever.
2) Your insurance auditors won't give you insurance for your
e-whatever unless you have 'redundant' connectivity.
> so i might seriously consider dual homing to separate pops of a
> single very reliable isp, and concentrating my energy on physical
> diversity of the local loop.
I believe you just limited yourself to an amazingly small number
of providers, if any at all. Even in the large metro areas where
providers _might_ have two POPs, they are often fairly dependant
on a third location (ie 60 Hudson, 1 Wilshire) which in many cases
could just be an aggregation POP for that provider in the region.
How many cities does Verio have two POP's in set up in such a way
that the loss of all or part of one POP would result in almost no
effect on the other POP?
> if i really felt the need for multiple providers, i might do a double
> nat, but with full 1:1 mapping, i.e. pure address aliasing, not space
> compression. of course, some persistent connections would be lost in
> the case of a link failure. but insurance against very rare cases is
> ok if the expense is incurred on the rare case.
You want to explain that in a bit more detail. Start with 'client
looks up www.example.com' and go to 'client establishes tcp connection
with the web server that services the content'.
Having DNS point at 2 IP's and having one "not be there" is not a
valid answer, it doesn't work in the real world.
--
Leo Bicknell - bicknell@ufp.org
Systems Engineer - Internetworking Engineer - CCIE 3440
Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org
