In this tutorial, we will show you how to add IPv6 addresses to your CentOS Server.

In this case, the network interface we will use in our tutorial will be eth0 and the IPv6 subnet will be a /120.

Add a temporary IPv6 address to your server

To add a temporary IPv6 to your server, use this command

ip -6 addr add IPv6_address/120 dev eth0

This IP can be use now but will be deleted at the next reboot of your server or a restart of the network.

Remove this temporary IPv6 address without reboot

To remove this temporary IPv6, use this command

ip -6 addr del IPv6_address/120 dev eth0

Add a static IPv6 address to your server

Edit the network interface eth0

nano /etc/sysconfig/network-scripts/ifcfg-eth0

And add the following block

...
IPV6INIT=yes
IPV6_PEERROUTES="yes"
IPV6_PRIVACY="no"
IPV6_AUTOCONF="yes"
IPV6_DEFROUTE="yes"
IPV6_FAILURE_FATAL="no"
IPV6ADDR=primary_ipv6_address/120
IPV6_DEFAULTGW=ipv6_gateway
...

Add additional IPv6 addresses to your interface

Add the following line to your network interface

IPV6ADDR_SECONDARIES="second_ipv6_address/120 third_ipv6_address/120 .../120"

The complete IPv6 block should look like this

...
IPV6INIT=yes
IPV6_PEERROUTES="yes"
IPV6_PRIVACY="no"
IPV6_AUTOCONF="yes"
IPV6_DEFROUTE="yes"
IPV6_FAILURE_FATAL="no"
IPV6ADDR=primary_ipv6_address/120
IPV6_DEFAULTGW=ipv6_gateway
IPV6ADDR_SECONDARIES="second_ipv6_address/120 third_ipv6_address/120 .../120"
...

Restart your network to bind your new IPv6 Addresses

CentOS 6

service network restart

CentOS 7

systemctl restart network