Looking for an IPv6 naysayer...

Wed Feb 9 21:33:51 UTC 2011

> 
> Comcast, like all(?) DOCSIS systems uses 10/8 or one of the other
> defined non-routable blocks for cable modems, which (if its a DOCSIS
> certified device) will be a bridge only and will not do NAT.  If you
> we're NAT'ed on a cable modem system it must have been a proprietary
> system, of which there once was a ton before DOCSIS caught on, that
> Comcast hadn't phased out.
> 
> I don't believe that any of the large MSO's (and none of the small
ones
> I know) are doing NAT on edge devices or the core at this point,
> however
> your point is still valid since virtually all of the ADSL lines

I can log in to the Two Wire device on my AT&T Uverse service and see
the NAT configuration.  It has a global IP on the Internet side and it
has a DHCP server handing out RFC1918 addresses on the inside network.
I can also configure some settings which allow certain applications
inside to map to specific ports on the global IP.

When I had Comcast, I am not positive where the NAT was being done, but
my computer got an RFC1918 IP when it did DHCP.