How to disable IPv6 on CentOS 5.5

The reason for this article is simple. The recommended method from CentOS wiki doesn’t work while the other method works. Here is what will disable IPv6 on CentOS Linux and also prevent the module from loading.

1. Edit /etc/sysconfig/network and set “NETWORKING_IPV6″ to “no”
   • This still loads the module but IPv6 is administratively disabled. Run the next command to prevent loading the ipv6 module
2. Then add the following to /etc/modprobe.conf :
   • alias ipv6 off
   • alias net-pf-10 off
3. Now reboot the machine.

That’s it!