使用ifconfig命令查看网卡信息，如果出现inet6 fe80::20c:29ff:fed0:3514，说明机器开启了ipv6

[root@MiWiFi-R3A-srv ~]# ifconfig
enp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.31.201  netmask 255.255.255.0  broadcast 192.168.31.255
        inet6 fe80::3ef8:d2:8709:a5ce  prefixlen 64  scopeid 0x20<link>
        ether 14:14:4b:e4:88:08  txqueuelen 1000  (Ethernet)
        RX packets 3105  bytes 375203 (366.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1651  bytes 269376 (263.0 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

编辑/etc/sysconfig/network配置，增加 NETWORKING_IPV6=no，保存并退出

[root@domain]$ vim /etc/sysctl.conf
 
# sysctl settings are defined through files in
# /usr/lib/sysctl.d/, /run/sysctl.d/, and /etc/sysctl.d/.
#
# Vendors settings live in /usr/lib/sysctl.d/.
# To override a whole file, create a new file with the same in
# /etc/sysctl.d/ and put new settings there. To override
# only specific settings, add a file with a lexically later
# name in /etc/sysctl.d/ and put new settings there.
#
# For more information, see sysctl.conf(5) and sysctl.d(5).
#
 
net.ipv6.conf.all.disable_ipv6=1

编辑/etc/sysconfig/network配置，增加 NETWORKING_IPV6=no，保存并退出