For security reason its always better tio disable IPV6 on Linus server, as IPV6 traffic is not filter by server firewall. Refer following steps to disable IPV6.

Login in to server as root user and open networking file.

root@server[~]#pico /etc/sysconfig/network

Add following two lines in the end of network file.

NETWORKING_IPV6=no
IPV6INIT=no

save network file  and restart network service or simply reboot server to implement changes