Add these lines to /etc/network/interfaces

iface eth0 inet6 static
        address 2001:1458:E008:0001::2
        netmask 64
        gateway 2001:1458:E008:0001::1
        pre-up modprobe ipv6

Add these lines to /etc/sysconfig/network-scripts/ifcfg-eth0
IPV6INIT=yes
IPV6ADDR=2001:1458:E00C::63/64

Add these lines to /etc/sysconfig/network
NETWORKING_IPV6=yes
IPV6_DEFAULTGW=2001:1458:E00C::1

• WARNING: SLC5 images have the ipv6 module disabled. Please edit the file /etc/modprobe.conf and remove the lines which disable ipv6 (#alias ipv6 off, #options ipv6 disable=1); then reboot.