[137121] in North American Network Operators' Group
Re: Looking for an IPv6 naysayer...
daemon@ATHENA.MIT.EDU (Iljitsch van Beijnum)
Wed Feb 9 15:17:26 2011
From: Iljitsch van Beijnum <iljitsch@muada.com>
In-Reply-To: <4D52E942.5000607@ispalliance.net>
Date: Wed, 9 Feb 2011 21:17:14 +0100
To: Scott Helms <khelms@ispalliance.net>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 9 feb 2011, at 20:21, Scott Helms wrote:
> IPv6 for some ISPs will be extraordinarily painful because of legacy =
layer 2 gear (usually DSLAMs that drop any frame with IPv6 in the =
EtherType field), inability to upgrade customer gear efficiently
[...]
> For ISPs in this circumstance the choice will be CGNAT rather than =
IPv6 for a number of years because the cost is much lower and according =
to the vendors selling CGNAT solutions the impact to end users is =
(almost) unnoticeable.
The good thing is that as an ISP, you don't have to give everyone the =
same thing. For the content people, it's either an AAAA record in the =
DNS or no AAAA record in the DNS. But as an ISP, you can keep your =
existing customers on existing IPv4 using existing hardware, while you =
roll out CGNAT + IPv6 for new customers using new gear. (Yes, that's =
still going to be annoying, but annoying in the sort of "I wish I didn't =
have to but I guess I do" kind of way rather than the "this will =
bankrupt the company" kind of way.)
As long as your "legacy" users have an IPv4 address they can always use =
tunneling to get IPv6 (you may want to set up a tunnel termination box =
for this) if they need IPv6. But they won't really _need_ IPv6 (at least =
not very soon) because they can set up port mappings etc and everything =
they need can work over IPv4.
For the new users, there are no port mappings behind the CGNAT so they =
do need IPv6 for hosting services and for VoIP and peer-to-peer file =
sharing. They also can't get a protocol 41 tunnel so you, their ISP, has =
to provide them with IPv6.
But just CGNAT with no IPv6 is going to be very bad. Maybe 95% of your =
users won't notice, but do you really want the other 5% to tie up your =
support lines?=
