[root@localhost ~]# tail -500f /var/log/messages
Dec 21 17:24:22 localhost dhclient[6639]: DHCPDISCOVER on ens160 to 255.255.255.255 port 67 interval 8 (xid=0x34689be7)
Dec 21 17:24:30 localhost dhclient[6639]: DHCPDISCOVER on ens160 to 255.255.255.255 port 67 interval 8 (xid=0x34689be7)
Dec 21 17:24:38 localhost dhclient[6639]: DHCPDISCOVER on ens160 to 255.255.255.255 port 67 interval 18 (xid=0x34689be7)
Dec 21 17:24:56 localhost dhclient[6639]: DHCPDISCOVER on ens160 to 255.255.255.255 port 67 interval 11 (xid=0x34689be7)
Dec 21 17:25:07 localhost dhclient[6639]: DHCPDISCOVER on ens160 to 255.255.255.255 port 67 interval 16 (xid=0x34689be7)
可以看出，一直有dhclient在请求服务。
ps -ef |grep dhclient
可以看到/sbin/dhclient再请求，最终取消我的ipv4的地址。
解决方法如下:
cd /sbin
mv dhclient dhclient-zsd
mv dhclient-script dhclient-script-zsd
移除上述应用。
