Comcast IPv6 and Fedora Linux

[achinhibitor.livejournal.com]

There doesn't seem to be much documentation out there, so I figured I'd repeat this here for anyone who needs to know it. To get IPv6 connectivity from Comcast if your computer is running Fedora Linux and you are using ifcfg=* files, the needed changes are:

In /etc/sysconfig/network:

NETWORKING_IPV6=yes

In /etc/sysconfig/network-scripts/ifcfg-em1:

IPV6INIT=yes
IPV6_AUTOCONF=yes
DHCPV6C=yes

Comcast uses "stateful DHCPv6" for handing out IPv6 addresses and address prefixes. All of this assumes that your computer is directly connected to the cable modem, rather than through a router box that takes care of IPv6 itself.

Comments

[dmaze]

This works out-of-the-box on the upcoming Ubuntu 14.04 release (with a brand-new Comcast-provided cable modem/wireless access point, I have an address in 2601:6:7e80:830::/64)...and somewhat to my surprise I can traceroute6 to archive.ubuntu.com.

[achinhibitor.livejournal.com]

upcoming

You mean, it's supposed to work on the upcoming release. You won't know if it does work until the release is out.

[siderea]

No, I think dzm is saying that they are already running Ubuntu 14.04, and they have found it to work out-of-the-box.

While Ubuntu 14.04 is not officially being released until the 17th, it's been in beta since...late March? So dzm could be running it. You can too, if you'd like.

[avacon.livejournal.com]

Good to hear it is working for folks here now. I guess I'll need to switch over from RCN as they responded to me a few weeks ago that they have IPv6 roll-out plans.

http://test-ipv6.com/ is also useful for checking whether IPv6 is working properly.

Context for anyone for whom this post makes no sense: IPv6 is an evolution of the underlying Internet Protocol (IP) which has been almost 20 years in the making and which Comcast is in the process of rolling out nation-wide, and I've heard they reached parts of the Boston area in the past few weeks. Comcast is rolling it out in a "dual-stack" mode meaning people keep their IPv4 addresses as well for now. See http://www.comcast6.net/ for more info.