在CentOS7上關閉IPv6

CentOS官方的Wiki提供了在7上關閉IPv6的方法。英文如下
5. How do I disable IPv6?
Upstream employee Daniel Walsh recommends not disabling the ipv6 module, as that can cause issues with SELinux and other components, but adding the following to /etc/sysctl.conf:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

To disable in the running system:

echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6




echo 1 > /proc/sys/net/ipv6/conf/default/disable_ipv6

or

sysctl -w net.ipv6.conf.all.disable_ipv6=1
sysctl -w net.ipv6.conf.default.disable_ipv6=1

Additional note #1: If problems with X forwarding are encountered on systems with IPv6 disabled, edit /etc/ssh/sshd_config and make either of the following changes:
(1) Change the line

#AddressFamily any

to

AddressFamily inet

(inet is ipv4 only; inet6 is ipv6 only)
or
(2) Remove the hash mark (#) in front of the line

#ListenAddress 0.0.0.0

Then restart ssh.
Additional note #2: If problems with starting postfix are encountered on systems with IPv6 disabled, either
(1) edit /etc/postfix/main.cf and comment out the localhost part of the config and use ipv4 loopback.

#inet_interfaces = localhost




inet_interfaces = 127.0.0.1

or
(2) take out the ipv6 localhost from /etc/hosts .
Additional Note #3 : To disable RPCBIND ipv6 (rpcbind, rpc.mountd, prc.statd) remark out the udp6 and tcp6 lines in /etc/netconfig:

udp tpi_clts v inet udp - -
tcp tpi_cots_ord v inet tcp - -
#udp6 tpi_clts v inet6 udp - -
#tcp6 tpi_cots_ord v inet6 tcp - -
rawip tpi_raw - inet - - -
local tpi_cots_ord - loopback - - -
unix tpi_cots_ord - loopback - - -

引自 http://wiki.centos.org/FAQ/CentOS7