On Wed, 1 Feb 2012, Brian E Carpenter wrote:
On 2012-02-01 08:14, Pete Resnick wrote:
On 1/31/12 11:59 AM, George, Wes wrote:
From: Noel Chiappa [mailto:jnc(_at_)mercury(_dot_)lcs(_dot_)mit(_dot_)edu]
Is that wise? I thought (IIRC, and maybe I'm spacing) the
whole reason for allocating this space was that 1918 space
_couldn't_ easily be used for CGN because there were too many
conflicting usages.
[WEG] yes, but the general sense I got from the ensuing discussion was
that no one expects anyone to actually adhere to that advice (ie MUST
NOT be used as substitute for 1918 space), and as soon as the space is
released, it'll be "cats and dogs living together, mass hysteria..."
because everyone and their cousin will start using it as 1918-bis
anyway, no matter whether the IETF wags their fingers at them or not.
I have no doubt that this space will be (mis)used as additional
private ambiguous address space. But IMHO the text should make it
clear that this is the wrong way to use it and give the reasons
why - basically the same information as in the new text, but stated
exactly the other way round. For example
Shared Address Space is IPv4 address space designated for Service
Provider use with the purpose of facilitating CGN deployment.
Shared Address Space is not intended to be used as additional [RFC1918]
space, because either or both of the following issues might arise:
o Shared Address Space could also be used on the Service Provider side
of the CPE, with overlapping subnet or host addresses.
o Some CPE routers behave incorrectly when using the same address block
on
both the internal and external interfaces.
Speaking as one of the bozos^h^h^h^h^h ADs whose comments (and suggested
text) ended the document up here, let me suggest the slightly less
pessimistic view from Wes's, and the reason that I think this
*shouldn't* specifically update 1918:
This *is* a special use address block that is akin to 1918. It is
non-routable address space, just like 1918. But unlike 1918, this block
is defined as "might be used by your ISP on your outside interface". So,
people using it inside their networks (which, I agree with Wes, will
happen, and like everything else on the net, will be done stupidly by
some) have been told that this is *not* private use space and that they
use it at their own risk and their CGN service might stop working if
they use it in a way not described in this document. But I'd hate for us
to allocate space to "CGNs only" when it's obvious that this can be used
for a whole class of these sorts of things, and can be used by other
people who build sane equipment that understands "shared" addresses can
appear on two different interfaces. These aren't "private" addresses a
la 1918, they're "shared", so it's not an addition to that space. Let's
properly document what it is we're doing, giving people fair warnings.
Exactly, hence my suggested text above.
+1
//cmh
_______________________________________________
Ietf mailing list
Ietf(_at_)ietf(_dot_)org
https://www.ietf.org/mailman/listinfo/ietf