1.9. 验证 DNS 解析

流程

1. 确保主机名和本地主机正确解析：

   # ping -c1 localhost
   # ping -c1 `hostname -f` # my_system.domain.com

   成功进行名称解析会导致输出类似如下：

   # ping -c1 localhost
   PING localhost (127.0.0.1) 56(84) bytes of data.
   64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.043 ms
   
   --- localhost ping statistics ---
   1 packets transmitted, 1 received, 0% packet loss, time 0ms
   rtt min/avg/max/mdev = 0.043/0.043/0.043/0.000 ms
   
   # ping -c1 `hostname -f`
   PING hostname.gateway (XX.XX.XX.XX) 56(84) bytes of data.
   64 bytes from hostname.gateway (XX.XX.XX.XX): icmp_seq=1 ttl=64 time=0.019 ms
   
   --- localhost.gateway ping statistics ---
   1 packets transmitted, 1 received, 0% packet loss, time 0ms
   rtt min/avg/max/mdev = 0.019/0.019/0.019/0.000 ms

2. 为了避免使用静态和临时主机名的差异，请输入以下命令设置系统中的所有主机名：

   # hostnamectl set-hostname name