[148912] in North American Network Operators' Group
Re: using ULA for 'hidden' v6 devices?
daemon@ATHENA.MIT.EDU (Tim Chown)
Thu Jan 26 05:42:20 2012
From: Tim Chown <tjc@ecs.soton.ac.uk>
In-Reply-To: <CALFTrnPV69sF2dRKxSObrnU4rJ2OXyWdk8e0Ns8f=k1rB4S4rg@mail.gmail.com>
Date: Thu, 26 Jan 2012 10:41:17 +0000
To: NANOG list <nanog@nanog.org>
X-ECS-MailScanner-From: tjc@ecs.soton.ac.uk
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
So the issue of ULAs has come up in the IETF homenet WG. The homenet WG =
is considering routing, prefix delegation, security, naming and service =
discovery.=20
ULA support is written into RFC6204 (basic IPv6 requirements for CPE =
routers) so home CPEs should have the capability, and should be able to =
generate "random" ULA prefixes.
The potential advantage of ULAs is that you have a stable internal =
addressing scheme within the homenet, while your ISP-assigned prefix may =
change over time. You run ULAs alongside your PA prefix. ULAs are not =
used for host-based NAT. The implication is that all homenet devices =
carry a ULA, though whether some do not also have a global PA address is =
open for debate.
There's a suggestion that ULAs could be used to assist security to some =
extent, allowing ULA to ULA communications as they are known to be =
within the homenet.
The naming and service discovery elements should remove the need to ever =
manually enter a ULA prefix; thus the temptation to use 0 instead of =
random bits for the ULA prefix should be reduced (even if the CPE allows =
it).
Prefix delegation of ULAs within a homenet would be done the same way as =
for the global PA prefix.
There is a proposal (not from within the homenet WG) to use ULAs with =
NPT66 (RFC6296). That obviously has some architectural implications.
Tim=
