- 不要直接手动修改文件 /etc/resolv.conf
安装好Ubuntu之后设置了静态IP地址，再重启后就无法解析域名。想重新设置一下DNS，打开/etc/resolv.conf
cat /etc/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
内容是一段警告：说这个文件是resolvconf程序动态创建的，不要直接手动编辑，修改将被覆盖。
root@Ubuntu14:~# cat /etc/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 nameserver 100.100.2.138 nameserver 100.100.2.136 options timeout:2 attempts:3 rotate single-request-reopen root@Ubuntu14:~#
ubuntu修改DNS有如下两种方法。
- 方法一：修改文件/etc/resolvconf/resolv.conf.d/base
root@Ubuntu14:~# cat /etc/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 nameserver 100.100.2.138 nameserver 100.100.2.136 options timeout:2 attempts:3 rotate single-request-reopen root@Ubuntu14:~# vim /etc/resolvconf/resolv.conf.d/base root@Ubuntu14:~# cat !$ cat /etc/resolvconf/resolv.conf.d/base nameserver 223.5.5.5 nameserver 223.6.6.6 root@Ubuntu14:~# resolvconf -u root@Ubuntu14:~# cat /etc/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 nameserver 100.100.2.138 nameserver 100.100.2.136 nameserver 223.5.5.5 options timeout:2 attempts:3 rotate single-request-reopen root@Ubuntu14:~# nslookup www.baidu.com Server: 100.100.2.138 Address: 100.100.2.138#53 Non-authoritative answer: www.baidu.com canonical name = www.a.shifen.com. Name: www.a.shifen.com Address: 220.181.112.244 Name: www.a.shifen.com Address: 220.181.111.188 root@Ubuntu14:~#
- 方法二：修改文件 /etc/network/interdaces
root@iZbp1b66g5htibj2m7yyv3Z:~# cat /etc/network/interfaces auto lo iface lo inet loopback auto eth0 iface eth0 inet dhcp dns-nameservers 223.5.5.5 # 在最后添加这一行
- 常用命令
linux刷新dns的缓存方法是： sudo /etc/init.d/nscd restart
最暴力的方法刷dns，重启网络： sudo /etc/init.d/networking restart
查看当前DNS解析情况：
nslookup www.baidu.com
dig | grep SERVER
root@iZbp1b66g5htibj2m7yyv3Z:~# /etc/init.d/nscd restart * Restarting Name Service Cache Daemon nscd [ OK ] root@iZbp1b66g5htibj2m7yyv3Z:~# /etc/init.d/networking restart stop: Job failed while stopping start: Job is already running: networking root@iZbp1b66g5htibj2m7yyv3Z:~# dig |grep SERVER ;; SERVER: 100.100.2.138#53(100.100.2.138) root@iZbp1b66g5htibj2m7yyv3Z:~# nslookup www.baidu.com Server: 100.100.2.138 Address: 100.100.2.138#53 Non-authoritative answer: www.baidu.com canonical name = www.a.shifen.com. Name: www.a.shifen.com Address: 220.181.111.188 Name: www.a.shifen.com Address: 220.181.112.244 root@iZbp1b66g5htibj2m7yyv3Z:~#