FC6: disable IPv6 network support

Disable IPv6 Networking Support to decrease unneeded system load if you're not going to use it anyway.

Edit /etc/sysconfig/network. (a restart of the network service is required)
[root@server ~]$ vi /etc/sysconfig/network
Change:
NETWORKING_IPV6=yes
To:
NETWORKING_IPV6=no

Disable IPv6 Protocol Stack for Kernel
Edit /etc/modprobe.conf.
[root@server ~]# vi /etc/modprobe.conf

Add the following 2 lines: (a restart of the network service is required)
alias net-pf-10 off
alias ipv6 off

Stop and disable IPv6 Firewall
[root@server ~]# /etc/init.d/ip6tables stop (or service ip6tables stop)
Flushing firewall rules:                                   [  OK  ]
Setting chains to policy ACCEPT: filter                    [  OK  ]
Unloading ip6tables modules:                               [  OK  ]

[root@server ~]# chkconfig –level 35 ip6tables off