IPv6 is a major component found within the Centos operating system and by following this guide you can completely disable IPv6 on the system. For those networks that do not support this feature disabling IPv6 can be a good option in order to tighten system security and increase the overall performance of the system.
It is not advised to use this method if you are intending to use any IPv6 dependent features such as Bonding, Postfix, SELinux and similar packages.
To begin, log in as root and disable IPv6 by typing
This ensures that whenever the system needs to load the IPv6 module, it is forced to execute the true command instead of actually loading the module; and as /bin/true does and means nothing, the module will not load.
Now disable the ipv6 tables
# chkconfig ip6tables off
Then we disable any calls to IPv6 in it’s various locations. To do this open the network configuration file.
# vi /etc/sysconfig/network
Scroll down and add or amend the following line to read
To complete the process we modify the configuration file for each Ethernet device to show the following values as an example
# vi /etc/sysconfig/network-scripts/ifcfg-ethx (x = 0,1 etc)
Reboot the system to complete.