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.