[101288] in North American Network Operators' Group
Re: v6 subnet size for DSL & leased line customers
daemon@ATHENA.MIT.EDU (Mark Smith)
Thu Dec 27 07:24:28 2007
Date: Thu, 27 Dec 2007 22:49:47 +1030
From: Mark Smith <nanog@85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org>
To: Iljitsch van Beijnum <iljitsch@muada.com>
Cc: sthaug@nethelp.no, nanog@merit.edu
In-Reply-To: <E1C97575-EE9B-411D-9D54-222C125DD5CA@muada.com>
Errors-To: owner-nanog@merit.edu
On Thu, 27 Dec 2007 12:11:54 +0100
Iljitsch van Beijnum <iljitsch@muada.com> wrote:
>
> On 27 dec 2007, at 11:57, sthaug@nethelp.no wrote:
>
> > "Configure this stuff manually" may work for a small number of
> > customers. It is highly undesirable (and probably won't be considered
> > at all) in an environment with, say, 1 million customers.
>
> Of course not. But RAs on a subnet with a million customers doesn't
> work either, nor does DHCP on a subnet with a million customers.
>
> If we're talking about provisioning cable/DSL/FTTH users, that's a
> completely different thing. Here, DHCPv6 prefix delegation to a CPE
> which then provides configuration to hosts on its LAN side would be
> the most appropriate option. However, the specifics of that model need
> to be worked out as there are currently no ISPs and no CPEs that do
> that, as far as I know.
I haven't had a chance to test it, but according to "Deploying IPv6
Networks", IOS can support DHCPv6 based prefix delegation. It even
supports multiple downstream interfaces on the CPE - you configure the
subnet number you want on each of the interfaces, and the CPE will
configure the DHCP-PD learned /48 on the front of them automatically
and then start announcing those prefixes in RAs out those interfaces.
Regards,
Mark.
--
"Sheep are slow and tasty, and therefore must remain constantly
alert."
- Bruce Schneier, "Beyond Fear"
