[97128] in North American Network Operators' Group
NAT Multihoming (was:Re: NANOG 40 agenda posted)
daemon@ATHENA.MIT.EDU (Lamar Owen)
Sat Jun 2 10:33:18 2007
Date: Sat, 2 Jun 2007 10:31:05 -0400
From: "Lamar Owen" <lowen@pari.edu>
To: nanog@nanog.org
In-Reply-To: <20070602002014.GB29581@cisco.com>
Errors-To: owner-nanog@merit.edu
On Friday 01 June 2007, Vince Fuller wrote:
> If you think about it, the NAT approach actually offers the possibility of
> improved routing scalability: site multihomed with NATs connected to each
> of its providers could use topologically-significant (read "PA") global
> addresses on the NATs while using the same private address space on their
> network.
Cisco has a whitepaper entitled "Enabling Enterprise Multihoming with Cisco
IOS NAT" that addresses this. See
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a0080091c8a.shtml
as well as RFC2260.
There are indeed a few thorny issues with this approach; the largest issue is
that all connectivity becomes DNS-dependent and raw IP addresses (from both
the inside and outside) become virtually useless. Running servers behind
this scheme, while doable, is difficult.
--
Lamar Owen
Chief Information Officer
Pisgah Astronomical Research Institute
1 PARI Drive
Rosman, NC 28772
(828)862-5554
www.pari.edu
