问题原因

Ubuntu 系统中 /etc/resolv.conf 其实是一个软连接（Link），它其实指向的是 /run/resolvconf/resolv.conf。如果需求开机不进行自动还原，需要修改上述文件。

也可以直接修改网卡配置文件，或者修改 /etc/resolvconf/resolv.conf.d/tail 文件后通过 resolvconf -u 命令进行更新。

解决方案

可以参阅如下步骤进行修改和调整：

1、修改 /run/resolvconf/resolv.conf

$ vi /run/resolvconf/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
options timeout:1 attempts:1 rotate
nameserver 223.5.5.5
nameserver 223.6.6.6

2、在网卡配置文件 /etc/network/interfaces 里面添加相应 DNS 服务器地址，比如：dns-nameservers 223.5.5.5 223.6.6.6

$ vi /etc/network/interfaces
auto lo
iface lo inet loopback
auto eth1
iface eth1 inet static
address 112.*.*.131
netmask 255.255.252.0
dns-servers 223.5.5.5 223.6.6.6
up route add -net 0.0.0.0 netmask 0.0.0.0 gw 112.*.*.247 dev eth1
auto eth0
iface eth0 inet static
address 10.*.*.214
netmask 255.255.240.0
up route add -net 172.16.0.0 netmask 255.240.0.0 gw 10.*.*.247 dev eth0
up route add -net 100.64.0.0 netmask 255.192.0.0 gw 10.*.*.247 dev eth0
up route add -net 10.0.0.0 netmask 255.0.0.0 gw 10.*.*.247 dev eth0
~

3、修改 /etc/resolvconf/resolv.conf.d/tail ,然后通过 resolvconf -u 命令进行更新：

$ vi /etc/resolvconf/resolv.conf.d/tail 
options timeout:1 attempts:1 rotate
nameserver 223.5.5.5
nameserver 223.6.6.6
root@iZ28ig469cdZ:~# resolvconf -u

Stopped Name Service Cache Daemon: nscd.



Starting Name Service Cache Daemon nscd

...done.