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Comcast Activates IPv6 Trial Users

Posted by timothy on from the hop-aboard-the-six-train dept.

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."

27 of 214 comments (clear)

  1. NT by wasabii · · Score: 2

    It's actually the only solution.

    1. Re:NT by dgatwood · · Score: 2

      NT... It's actually the only solution.

      Did you leave out an "A" in the middle of that?

      --

      Check out my sci-fi/humor trilogy at PatriotsBooks.

    2. Re:NT by TheRaven64 · · Score: 2

      First: IPv4 is actually embedded in the IPv6 address space in a few places, for different tunnelling mechanisms, 6to4 being one of them. Secondly, how do you think that would avoid the need for dual-stack solutions? Even ignoring the fact that v6 and v4 packet headers are completely different, v4 hosts can't just talk to v6 hosts using magic. What do you expect an IPv4 client to do when it sees a server with an IPv6 address?

      --
      I am TheRaven on Soylent News
  2. Comcast really? by magsol · · Score: 2

    To be honest, they're the last ISP I'd have expected to start IPv6 implementation.

    --
    "I'd just like to emphasise that taking a million years isn't a metaphor here..." -Rich Bradshaw
    1. Re:Comcast really? by rritterson · · 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.

      --
      -Ryan
      AUWYHSTOT (Acronyms are Useless When You Have to Spell Them Out Too)
    2. Re:Comcast really? by sjames · · Score: 2

      They seem like two different operations. The behind the scenes people seem to be good, but their phone support people seem to be entirely clueless and trained to lie as a matter of policy. If they really want to be more profitable, they should try actually performing diagnostics before dispatching someone for inside support when the problem usually turns out to be on the lines outside (which requires a second dispatch to solve, the inside techs aren't equipped for it).

    3. Re:Comcast really? by petermgreen · · Score: 5, Insightful

      Comcast has a slightly unusual situation. They are so massive that their "control plane" network has exhausted 10.0.0.0/8. That means afaict they are now using public IPs not just for customers but for internal use as well. The space that most ISPs would use to put their customers on ISP level NAT is ALREADY TAKEN for their "control plane" network.

      http://www.nanog.org/meetings/nanog37/presentations/alain-durand.pdf

      Given that they have little choice but to go IPv6 for thier internal networks (or "federate" the network but that is a large management headache) before IPV4 addresses run out it is not that surprising that they are proposing to offer it to customers as well.

      --
      note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
  3. Famous Last Words by mccrew · · Score: 5, Funny

    Each user has been delegated a /64 block of approximately 18,446,744,073,709,551,616 (18 quintillion) unique IPv6 addresses.

    "18 quintillion unique IPv6 addresses should be enough for anybody." -me

    --
    Hey, Windows users, there is no such thing as "forward" slash, there is only slash and backslash.
    1. Re:Famous Last Words by SmilingBoy · · Score: 2

      Actually, this is not enough. IPv6 always uses /64 subnets. The standard policies suggest that an ISP should allocate a block of /48 to /56 to each end user. This means that every end user can have 256 to 65,536 /64 subnets. Furthermore, the standard policies say that /19 to /32 should be allocated to each ISP.

      I agree that it sounds wasteful, but it should be possible without problems.

      Assume an allocation of /48 to each end user (actual numbers: /48 to /64). This means every end user can run 65,536 networks.

      Further assume an allocation of /24 to each ISP (actual numbers: /19 to /32). This means every ISP can have 16,777,216 end users.

      Finally, assume that only the 2000::/3 block of the address space will be used (as per current allocations). This means we can have 2,097,152 ISPs.

      However, I think that eventually, SOHO end user will only be allocated /56 blocks as this is simply more than enough.

      Importantly, manufacturers of routers and software should not make the assumption that anything outside 2000::/3 is an invalid address. This way, in case 2000::/3 runs out of space, we can have different allocation policies for the rest of the address space.

      I have my IPv6 connectivity via SixXS, where you get allocated a /48 (for free).

  4. Re:Each user gets 18 quintillion addresses? by kimvette · · Score: 2

    Well, folks have thought better of this and decided that they had to plan for the day where we develop nanotech medicine, and have an IP address available for each cell-nanotech pair for an entire family, plus enough overhead to give the same for each pet.

    --
    The Christian Right is Neither (Christian nor right). See: Matthew 23, Matthew 25, Ezekiel 16:48-50
  5. Good by wasabii · · Score: 2

    The point of this is to uncover any issues with customer equipment that prevents it. Any modern Vista or Windows 7 box by default has IPv6 enabled, and it works just fine. I know. I use it on all of my company's machines. Any devices that isn't aware of IPv6 will just ignore it. I'm expecting some poor IPv6 translation technologies on cheap routers that break with real IPv6 presence. That's kind of the only downside I can imagine.

    Customers behind an existing IPv4-only NAT device won't even be touched.

  6. Re:why? by sirambrose · · Score: 2

    They probably want customers to use native ipv6 so they can eventually stop supporting native ipv4. I believe they are planning to let people run ipv6 exclusively and proxy outbound ipv4 connections which seems like a better long term strategy. I don't think that giving customers a new modem and router will complicate the rollout too much.

  7. Re:why? by Anonymous Coward · · 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.

  8. Re:why? by wasabii · · Score: 2

    I should also mention that running IPv4 over IPv6 is kind of weird, and presents more problems than a proper dual stack.

  9. Apple base stations, some D-Links, some Linksys by YesIAmAScript · · Score: 2

    http://en.wikipedia.org/wiki/6to4#Consumer_routers_with_6to4_support

    http://www.comcast6.net/

    Apple's base stations are certified IPv6 ready, which means not only do they work with IPv6, but they have it on by default. The others might require you turn it on. Instructions on how to set up some of them are on Comcast's site.

    I've had Comcast internet for two years, they haven't MAC-locked their service in the time I've had them. If you want more than one device at your house to work, you need a NAT/PAT gateway whether you use WiFi or not, as you only get a single IP address from Comcast.

    --
    http://lkml.org/lkml/2005/8/20/95
  10. Re:In related news... by ZorinLynx · · Score: 3, Insightful

    Big heavy winter storms can do that, yes.

  11. Re:Each user gets 18 quintillion addresses? by Sancho · · Score: 2

    MAC addresses are 64-bit. By handing out a /64 prefix to the user, a bit of convenience can be achieved wherein the MAC address of the adapter is automatically used as the last 64-bits of the user's IPv6 address.

  12. Re:Each user gets 18 quintillion addresses? by Sancho · · Score: 2

    I had a bit of a brain fart there. MAC addresses are obviously 48-bit. Nonetheless, the same magic can happen with 64-bit prefixes, though you could obviously get better utilization with a larger prefix.

  13. Re:Each user gets 18 quintillion addresses? by rabbit994 · · Score: 2

    /64 is RFC recommended because IPv6 Autoconfiguration uses your NIC MAC address to generate IPv6 address for itself. The length of /64 is same as MAC address. That's why they are doing it.

    IPv6 was designed to have large amount of waste built in. When you have 3.4x10^38, you can afford to be a little wasteful.

  14. Re:They don't want to NAT by petermgreen · · Score: 2

    Afaict the original idea with ipv6 was to go from public v4-->ubuiquitous dual stack with public v4-->phaseout of public v4.

    However there is a chicken and egg situation, ISPs won't want to put users on v6 only until the majority of websites are available on v6 and a substatial proportion of website owners won't see any point in offering v6 while all their clients can still access v4. Especially as a lot of people who do have v6 have it via tunnels that add latency and reduce reliability. The result is a smooth and speedy transition of the internet to dual stack is unlikely.

    So in a world of scarce IPs the ISPs will have little option but to give some customers natted v4. They may or may not give those customers v6 as well.

    --
    note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
  15. Re:why? by zach_the_lizard · · Score: 2

    I don't know about Comcast for sure, but some of the cell phone companies, at the very least, have multiple private blocks each.

    --
    SSC
  16. Re:Each user gets 18 quintillion addresses? by Anonymous Coward · · 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).

  17. This is ridiculous by ugen · · Score: 2, Interesting

    "Each user has been delegated a /64 block of approximately 18,446,744,073,709,551,616 (18 quintillion) unique IPv6 addresses. "

    So, effectively, they just shortened an IPv6 address to 64 bit - and allocation haven't even started yet in earnest.
    This is the problem with people. Even technical people (and moreover - everyone else) will waste any resource (including artificial resource) until there is scarcity regulated by monetary means. If that's the way IPv6 will be assigned - /64 to an individual user, /32 to a corporation, /12 to interplanetary internet or whatever other cooky idea there is - these addresses will run out in a jiffy. And then we'll be trading in these and IPv4 just the same.

    1. Re:This is ridiculous by Nigel+Stepp · · Score: 5, Informative

      Give rfc3177 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.

      --
      4096R/EF7BAFA6 79E1 DF98 D09D 898F 9A11 F6F0 DDDC 23FA EF7B AFA6
  18. Re:why? by WaffleMonster · · Score: 2

    Sorry, at a loss. comcast should just keep ipv4 internal and proxy ipv6 externally. Don't understand the reason to complicate its implementation any more. Other than let us geeks suffer the consequences

    When IPv4 addresses are no longer available(Coming within just months to a RIR near you! IANA global pool already gone!!) how do you propose to use IPv4 internally when the necessary IPv4 address space simply does not exist?

    I can see an ISP following your advice right up until they need to fill out a new SWIP request for address space that does not exist. RIR: sorry dude.. ISP to customer: sorry dude... customer: @*(@#**!

    When IPv4 runs out the only avenue for not switching to IPv6 for new users is CGN... given the choice I would rather have a monsterous IPv6 address than stay with IPv4 and go through a carrier NAT loosing the ability to connect to my stuff from the network and run my own servers.

    Comcast and the rest of the world are extremely late on IPv6 deployment. Slashdots... oh slashdot... tears come to my eyes just thinking about slashdots lack of IPv6 support. It is really sad.

    If you care about a global network that can accomodate everyone on the planet equally as peers IPv6 is the only answer available. I believe the developing world should have the same opportunties as the developed world.

    Unfortunatly the number of naysayers who either do not care, do not want to change or do not see the big cluster*@*# on the horizion due to v4 depletion even with IPv6 deployment is still quite large.

      I don't know what to say or how to convinence people they need to take IPv6 seriously. After all it is not your problem...why should you care?

  19. Re:Slightly unrelated by WaffleMonster · · Score: 2

    I want to go to a *single* IP address that represents all systems on my network. Same thing I am doing today with IPv4. I don't like people outside to be able to enumerate devices on my network - and using a single address is a first step (tweaking IP stacks to change signature and replacing browser agent string helps too).

    It is possible today to recover the users internal IP address on their private IPv4 network using flash / javascript when they visit a web site.

    NAT == stateful firewall without packet mangling.

    Effectivly anyone who wants it gets the same information and capabilities from your users regardless of IPv4 NAT vs IPv6 firewall.

  20. Re:Slightly unrelated by cyclomedia · · Score: 2

    As per request I'll refrain from saying "that's not what you need" but still. They wont be able to "enumerate" if you have a firewall, you don't need NAT to block incoming ports. I prepared these diagrams and post links whenever this is discussed on slashdot:

    IPv4 NAT : http://cyclomedia.co.uk/blog/media/nat.png

    IPv6 Firewall : http://cyclomedia.co.uk/blog/media/ipv6.png

    Note the devices in the house that don't have any incoming ports. Not even ping? Note how it's the same in both diagrams? Do you get it yet?

    --
    If you don't risk failure you don't risk success.