At last, I have IPv6

Many of the readers of this may already have IPv6.  My ISP, AT&T, has been a bit slow.  Two years ago, they said we would have IPv6 by the end of June.  They did not make that date.

I’m using their U-verse service, with a 2Wire 3800HGV-B gateway router.  On May 20, there was a discussion thread at dslreports, about a new firmware release.  Someone reported that this new firmware provided IPv6 support.  Checking my router, I was still on the older firmware.  However, about 1 week later, I noticed that my firmware had been updated.

I went to the site to check IPv6 support for U-verse, and it said the router was now capable.  I clicked the link to have it configured.  And, shortly thereafter, my router was reporting IPv6.


My home setup had included a secondary router.  This was IPv6 capable, but I was not sure how well the double router would handle IPv6.  So, the next morning, I reorganized so that the computers are all directl connected to the 3800HGV-B.

Once I restarted networking on my main desktop, I had an IPv6 address.  I had shutdown other computers, to avoid the disruption of my reorganizing.  On reboot, they came up with IPv6 address (in addition to a LAN IPv4 address).

The addresses

On my desktop, I already had an IPv6 address that begins with “fe80::”.  That was just for LAN communication.  Now, I also had another address beginning “2602:306:”.  And that’s the address I could use to communicate outside the LAN.  The least significant bits of the new IPv6 address are based on the MAC address (or ethernet address).  I did not need to turn on DHCP for IPv6.  Networking was able to acquire addresses without using that.

Checking Windows boxes, they also had a local address beginning “fe80::” and a global address.  They actually had two global addresses.  One of those is fixed, and the other appears to be randomized.  Apparently, that’s an IPv6 feature.  You can make external connections with a randomized temporary address.  The fixed IP address for windows is not based on the MAC address.  That also seems to be randomized, but remembered so that the same address is used for each boot.

The windows boxes also have the teredo IPv6 address configured by Windows, but I presume that won’t be used.


I’ve been surprised at how many IPv6 connections I have been making.  I had assumed that most connections would continue to use IPv4.  But it appears that if a site has an IPv6 address, that is used by preference.

It all seems to be working well.  I have downloaded an iso, where the download happened to use IPv6.  And the speed is about the same as I have usually seen in the past.


About Neil Rickert

Retired mathematician and computer scientist who dabbles in cognitive science.

5 responses to “At last, I have IPv6”

  1. Jason Fesler says :

    I find this part unfortunate:

    “I went to the site to check IPv6 support for U-verse, and it said the router was now capable. I clicked the link to have it configured.”

    IMO, this is something that AT&T will hopefully move to “opt out” instead of “opt in”. The average consumer should not know a darn thing about IPv4 vs IPv6; they should instead just have it work as they upgrade to modern gear. 😦


    • Neil Rickert says :

      I agree. Opt-out, rather than opt-in would be better.

      I think the problem is that they are having to redesign their backbone to support IPv6, so this is a transitional step.

      At present, we are getting 6rd, meaning that the IPv6 is tunneled via IPv4.


      • James Sutherland says :

        I’m glad to see AT&T offering it at last – here in the UK, IPv6 is still far too rare. (The small ISP I use now offers it; the only cable company has no stated plans beyond the same “we’re thinking about it” they’ve been saying for years, along with assurances they have “enough” IPv4 addresses.)

        I agree it’s nice to see how much traffic can already go via v6, and that should grow faster now – we’re finally seeing ISPs like AT&T and Comcast offering it to the public, and IPv4 addresses getting harder and harder to obtain for new services. Long overdue though!


        • Neil Rickert says :

          Long overdue though!

          Indeed. The ISPs have been far too slow on this.

          Probably sometime within the next two years, the usage will reach critical mass, and then quickly take over the Internet.


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