On Fri, 14 Oct 2005, David Conrad wrote:
Christopher,
(chris is fine, silly corp email doesn't let us have sane addresses :( )
On Oct 14, 2005, at 9:32 PM, Christopher L. Morrow wrote:
You know, if you describe it that way too many times, people who are only paying half-attention are going to say "IPv6 has something almost like NAT, only different". you know... shim6 could make 'source address' pointless, you COULD just do NAT instead :) or do shim6 which looks like NAT ... if you don't get the host auth parts correct/done-well you might even be able to send traffic off to the 'wrong' place :) it'll be neat!
I believe relying on the address as any sort of authentication is a mistake. Given IPv6 was, at least in theory, supposed to require
in v4 it's not used that way, in v6 I'd hope the trend continues. If there isn't some very good form of authentication built into the shim solution it may be possible for an attacker in the packet path (or who can guess well enough) to tell either endpoint that there was a path failure and it's time to use a new ip address for the current conversation. anyway, shim6 isn't hear yet, and I'm sure someone would have thought of this problem before :)
IPSEC, I would have thought the use of the source address for anything other than connection demultiplexing would have been a waste of time.
Of course, that assumes that people actually implement "required" parts of protocol specifications. As has been seen countless times, what happens in practice doesn't seem to conform to what is required in theory. Do all IPv6 stacks implement IPSEC?
Merike has some interesting information about this... from what I understand not everyone implemented all the 'required' parts :( I wonder how quickly SA's can be re-done for conversations in a shim world? will they have to be or could the SA be tied to the ULID? Probably also something fun for the shim folks to figure out. I'd hate to have to re-negotiate ipsec associations everytime I thought there was a path failure :(