On 12/01/2011 22:07, Ted Hardie wrote:But doesn't that same line of reasoning apply to any new allocation
> No, I think that premise is mis-stated. Premise 1: There exists
> equipment that can't handle identical addresses on the interior and
> exterior interface. Premise 2: it may be deployed now or in the future
> for customers using any part of the RFC 1918 allocation *because those
> using the RFC 1918 allocations had no prior warning that this might
> create a collision*. Conclusion: You cannot avoid identical addresses
> on the interior and exterior interface by using any part of the RFC 1918
> allocation.
that's made for this purpose? You can fix the problem for today, but you
can't fix it for the future because you can't prohibit customers from
using the new allocation on the inside of their network.
If a customer uses a CGN-specific allocation on the inside of their network as if it were RFC 1918 space, then, yes, they will have trouble if they ever use a provider that uses a CGN. At the very least, though, they have collaborated in their need to renumber by ignoring the quite plain warnings that this is a bad idea. They did not have that warning about using an allocation from RFC 1918 space.
Therefore, making the allocation is a pointless waste of resources that
can be better utilized elsewhere.
Step 1: Determine the most popular inside prefixes for CPEs
Step 2: Use the least popular RFC 1918 prefix for the CGN network
Step 3: If your customer has somehow chosen the same prefix, tell them
they can't do that.
And yes, I realize that Step 3 is going to be incredibly unpopular for
the ISPs, but they created the problem, so they should have to live with
the results.
It's not going to be unpopular with ISPs, it will be unpopular with *customers*. To retain those customers, the ISPs will simply ignore the RFC and use some other space. At least, that's my prediction.
regards,
Ted
Doug
--
"We could put the whole Internet into a book."
"Too practical."
Breadth of IT experience, and depth of knowledge in the DNS.
Yours for the right price. :) http://SupersetSolutions.com/
_______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf