IPv6 Address: 2001:0db8:100:f101::2
Once you have it set up you can use ping6 to ping something like sixxs.net and make sure everything is working as expected.
RedHat Based Distributions:
Documentation on the web for IPv6 seems to be sparse, or my GoogleFoo is getting worse. However there is information available in /usr/share/doc/initscripts-7.93.25.EL/sysconfig.txt on RedHat Enterprise Linux. There are two files to be edited: /etc/sysconfig/network and /etc/sysconfig/network-scripts/ifcfg-eth0. In /etc/sysconfig/network you have to add the following two lines:
NETWORKING_IPV6=yesIn /etc/sysconfig/network-scripts/ifcfg-eth0 add the following:
IPV6INIT=yesOnce both files are saved, you can run "service network restart" in order to bring the changes into effect. Debian Based Distributions: In Debain and Ubuntu there is only one file to be editted, /etc/network/interfaces. You add the following:
iface eth0 inet6 staticOne the file has been saved, run "/etc/init.d/networking restart".
Update: April 1st 2007 Posted updated to make more sense. I am now using IPs from the IPv6 Documentation Prefix. Thanks Colm.