[151103] in North American Network Operators' Group
Shim6, was: Re: filtering /48 is going to be necessary
daemon@ATHENA.MIT.EDU (Iljitsch van Beijnum)
Sun Mar 11 18:16:48 2012
From: Iljitsch van Beijnum <iljitsch@muada.com>
In-Reply-To: <4F5CF9D5.9050601@bogus.com>
Date: Sun, 11 Mar 2012 23:15:38 +0100
To: Joel jaeggli <joelja@bogus.com>
Cc: NANOG Mailing List <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 11 Mar 2012, at 20:15 , Joel jaeggli wrote:
>> The IETF and IRTF have looked at the routing scalability issue for a
>> long time. The IETF came up with shim6, which allows multihoming
>> without BGP. Unfortunately, ARIN started to allow IPv6 PI just in
>> time so nobody bothered to adopt shim6.
> That's a fairly simplistic version of why shim6 failed. A better =
reason
> (appart from the fact the building an upper layer overlay of the whole
> internet on an ip protocol that's largely unedeployed was hard) is =
that
> it leaves the destination unable to perform traffic engineering.
I'm not saying that shim6 would have otherwise ruled the world by now, =
it was always an uphill battle because it requires support on both sides =
of a communication session/association.
But ARIN's action meant it never had a chance. I really don't get why =
they felt the need to start allowing IPv6 PI after a decade, just when =
the multi6/shim6 effort started to get going but before the work was =
complete enough to judge whether it would be good enough.
> That fundementaly is the business we're in when advertising prefixes =
to more
> than one provider, ingress path selection.
That's the business network operators are in. That's not the business =
end users who don't want to depend on a single ISP are in. Remember, =
shim6 was always meant as a solution that addresses the needs of a =
potential 1 billion "basement multihomers" with maybe ADSL + cable. The =
current 25k or so multihomers are irrelevant from the perspective of =
routing scalability. It's the other 999,975,000 that will kill the =
routing tables if multihoming becomes mainstream.=
