Comcast Activates IPv6 Trial Users 214
Spacecase writes "Comcast announced the first group of trial users have been activated on their IPv6 Native Dual Stack solution. Considering the recent news about IPv4 addresses becoming scarce, this looks to be one of the better solutions to get out of the IPv4 problems."
Re:why? (Score:4, Informative)
Uhh, the entire reason they're moving to IPv6 is because IPv4 internally no longer works for them. They've exhausted 10.0.0.0 (it's only 16M IPs, after all), so moving to v6 is the only way they can keep their network manageable, without going to crazy, multi-layered NAT solutions.
Re:Comcast really? (Score:5, Informative)
I have been a comcast customer for 8 straight years now (give or take a few months)
Had the announcement broken 3 years ago, I would have agreed with you, but Comcast is on a long, upward trend in technical competitiveness.
They were the first major ISP to go DNSSEC, I believe, and have done DOCSIS 3.0 rollouts in most of their markets (we get cheap 20/4 service here, with a 50 down option available. Some parts of the service area have 100mbps down.) They also rolled out a bunch of 6to4 servers recently. While 6to4 is not a great technology, it is useful to have ISP servers, since my IPv6 traffic (auto tunneled via an Airport Extreme) goes through my local NOC and not first to wisconsin and then back to silicon valley as was the case before.
They still lag when it comes to technical support via phone, as they assume all of their customers are techno-illiterate, but I have to give them a lot of credit for being on the leading edge when it comes to their network and network technologies.
Re:Each user gets 18 quintillion addresses? (Score:2, Informative)
The interface identifier part (lower part of /64) can be anything, but you can use a MAC by inserting FEFF into the middle of it, like so:
(Your network prefix):4:8:15:FE:FF:16:23:42
This is known as EUI-64 MAC and is not required by the protocol - under Stateless Address Autoconfig, hosts pick their own address, and under DHCPv6 they're assigned sequentially. Using the EUI-64 is a lazy convention which we really shouldn't do anyway (it's basically putting hardware fingerprints on your packets).
Re:This is ridiculous (Score:5, Informative)
Give rfc3177 [ietf.org] a read, especially section 4. That RFC is obsolete now, but the math hasn't changed.
These numbers are ridiculously huge, and it is intended in the design that subnets would normally be sized at /64. Thinking of that as 18 quintillion addresses is thinking like IPv4. IPv6 is different, and you think in terms of subnets. There are also (since an address is 128 bits) 18 quintillion /64 networks. If we give each person on the planet 65536 /64s (that's a /48) then we have enough for 5000 times the current world population in the current pool of addresses, which is 1/8th the full IPv6 address space. If you use the whole space, then it's 40,200 times the world population.