Add IPv6 to RedHat and CentOS Systems How would I add an IPv6 address to my Redhat / CentOS based system? First you would want to make sure you have the /etc/sysconfig/network-scripts/network-functions-ipv6 script. sh-3.00# ls -l /etc/sysconfig/network-scripts/network-functions-ipv6 -rw-r--r-- 1 root root 42087 Jun 25 2008 network-functions-ipv6 sh-3.00# Now that the IPv6 script is on the system, the next step is to check if the net-pf-10 module is loaded. We can do this by running the following commands: sh-3.00# modprobe -c | grep net-pf-10 alias net-pf-10 ipv6 sh-3.00# The above output shows the system does have it. If the system did not have it, you would get this output. sh-3.00# modprobe -c | grep net-pf-10 alias net-pf-10 off sh-3.00# So if it is off on your system you would want to edit /etc/sysconfig/network and enable NETWORKING_IPV6. Here is an example of what a /etc/sysconfig/network with IPv6 would look like. sh-3.00# cat /etc/sysconfig/network NETWORKING=yes HOSTNAME=ipv6test.softlayer.com GATEWAY=10.12.12.1 NETWORKING_IPV6=yes sh-3.00# Now you will want to restart your networking service. You can do this via the /sbin/service network restart command. sh-3.00# /sbin/service network restart Shutting down interface eth0: [ OK ] Shutting down interface eth1: [ OK ] Shutting down loopback interface: [ OK ] Setting network parameters: [ OK ] Bringing up loopback interface: [ OK ] Bringing up interface eth0: [ OK ] Bringing up interface eth1: [ OK ] sh-3.00# Now you will want to edit your /etc/sysconfig/network-scripts/ifcfg-eth1 file to add the IPv6 parameters. Add the following IPV6INIT=yes IPV6ADDR=YOURIPV6ADDRESS IPV6_DEFAULTGW=YOURGATEWAY Here is an example of what a IPv6 portion should look like. #IPV6 configuration IPV6INIT=yes IPV6ADDR=2607:f0d0:2001:0000:0000:0000:0000:0010/64 IPV6_DEFAULTGW=2607:f0d0:2001:0000:0000:0000:0000:0001 After you add that you will want to restart your network services again sh-3.00# /sbin/service network restart Shutting down interface eth0: [ OK ] Shutting down interface eth1: [ OK ] Shutting down loopback interface: [ OK ] Setting network parameters: [ OK ] Bringing up loopback interface: [ OK ] Bringing up interface eth0: [ OK ] Bringing up interface eth1: [ OK ] sh-3.00# Now you should be able to communicate over IPv6. You can ping ipv6.google.com and see if it works. sh-3.00# ping6 ipv6.google.com –n PING ipv6.google.com(2001:4860:b002::68) 56 data bytes 64 bytes from 2001:4860:b002::68: icmp_seq=0 ttl=59 time=86.6 ms 64 bytes from 2001:4860:b002::68: icmp_seq=1 ttl=59 time=86.9 ms 64 bytes from 2001:4860:b002::68: icmp_seq=2 ttl=59 time=84.8 ms --- ipv6.google.com ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2003ms rtt min/avg/max/mdev = 84.870/86.130/86.913/0.961 ms, pipe 2 sh-3.00#