Disable IPV6 in centos 6.2

Disable IPV6 in centos 6.2
In Linux, IPv6 is supported by default, but enabling IPv6 will affect the network performance of some application servers that are not well supported by IPv6, after all, the current network switching device is not IPv6. How can I determine if ipv6 is enabled for the system? Run the lsmod | grep ipv6 limit 19392 0 iptable_mangle 3283 1 ipt_MASQUERADE 2400 3 iptable_nat 6124 1 nf_nat 22788 2 ipt_MASQUERADE, limit 9440 4 iptable_nat, limit 1449 1 limit 79643 5 ipt_MASQUERADE, iptable_nat, nf_nat, nf_conntrack_ipv4, xt_stateipt_REJECT 2349 2 iptable_filter 2759 1 ip_tables 17733 3 iptable_mangle, iptable_nat, ip Table_filter ipv6 23488114 second, you can also view the enabled port netstat-tln tcp 0 0 0.0.0.0: 8100 0.0.0.0: * LISTEN tcp 0 0 0.0.0.0: 3306 0.0.0.0: * LISTEN tcp 0 0 0.0.0.0: 843 0.0.0.0: * LISTEN tcp 0 0 0.0.0.0: 111 0.0.0.0: * LISTEN tcp 0 0 0.0.0.0: 80 0.0.0.0: * LISTEN tcp 0 0 0.0.0.0: 81 0.0.0.0: * LISTEN tcp 0 0 0.0.0.0: 113 0.0.0.0: * LISTEN tcp 0 0 0.0.0.0: 21 0.0.0.0: * LISTEN tcp 0 0 127.0.0.1: 631 0.0.0.0: * LISTEN tcp 0 0 0 12 7.0.0.1: 25 0.0.0.0: * LISTEN tcp 0: 8080: * LISTEN tcp 0 0: 22: * LISTEN tcp 0: 443 ::: * LISTEN udp 0 0 0.0.0.0: 68 0.0.0.0: * udp 0 0 0.0.0.0: 837 0.0.0.0: * udp 0 0 0.0.0.0: 840 0.0.0.0: * udp 0 0 0.0.0.0: 111 0.0.0.0: * udp 0 0 0.0.0.0: 631 0.0.0.0: * How can I disable it after it is enabled? I am using centos6.2 and cannot find/etc/modprobe. conf file, so I directly vi, and added two lines of alias net-pf-10 offalias ipv6 off and then echo "NETWORKING_IPV6 = NO">/etc/sysconfig/network to restart the system.