docker容器起来以后，查看端口监听情况，如下图：

[root@backup01 gcc-8.1.0]# ss -tnl
State       Recv-Q Send-Q                     Local Address:Port                                    Peer Address:Port              
LISTEN      0      100                            127.0.0.1:25                                                 *:*                  
LISTEN      0      128                                    *:3330                                               *:*                  
LISTEN      0      5                                      *:8911                                               *:*                  
LISTEN      0      100                                [::1]:25                                              [::]:*                  
LISTEN      0      128                                 [::]:3330                                            [::]:*                  
LISTEN      0      128                                 [::]:10051                                           [::]:*                  
LISTEN      0      128                                 [::]:33060                                           [::]:*                  
LISTEN      0      5                                   [::]:8911                                            [::]:*                  
LISTEN      0      128                                 [::]:80                                              [::]:*

端口10051，80，33060只监听在ipv6上，使用ipv4无法访问。

解决办法如下：

编辑/etc/default/grub，加入一行：

GRUB_CMDLINE_LINUX="ipv6.disable=1 ..."

保存后重新配置grub并重启服务器

# grub2-mkconfig -o /boot/grub2/grub.cfg

# reboot

重启后结果：

[root@backup01 ~]# ss -tnl
State       Recv-Q Send-Q                     Local Address:Port                                    Peer Address:Port              
LISTEN      0      128                                    *:3330                                               *:*                  
LISTEN      0      128                                    *:10051                                              *:*                  
LISTEN      0      128                                    *:33060                                              *:*                  
LISTEN      0      5                                      *:8911                                               *:*                  
LISTEN      0      128                                    *:80                                                 *:*                  
LISTEN      0      100                            127.0.0.1:25                                                 *:*

正常了。