1. DNS客户端配置 /etc/resolv.conf
[root@wenyuecs ~]# cat /etc/resolv.conf
options timeout:1 attempts:1 rotate single-request-reopen
; generated by /usr/sbin/dhclient-script
search localdomain
#nameserver 223.5.5.5
#nameserver 223.6.6.6
nameserver 100.100.2.136
nameserver 100.100.2.138