I remember that some distribution installers asked in the past if IPv6 should be enabled or not. Perhaps the Fedora installer did (or does) it as well.
How do I easily check a Fedora system (>= 17) if IPv6 was enabled/disabled during the installation?
Or how do I check if the Fedora system is ready for IPv6 enabled routers?
Use /sbin/ifconfig or /sbin/ip a l and look for any lines starting with inet6.
$ ip a l eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 00:11:22:33:44:55 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.5/24 brd 192.168.0.255 scope global eth0
inet6 fe00::000:00ff:febc:a0/64 scope link
valid_lft forever preferred_lft forever
lsmod |grep -i ip will show loaded IP-modules. If you see ipv6 modules parts are active.
If you see an IPv6-address as described by skohrs you are already able to configure an IPv6-address to an interface.
It does not matter what your cable is connected to (router, switch, crossover, ...).
Test if the path /proc/sys/net/ipv6 exists.
