当 resolv.conf 被覆盖时，如何设置我的 DNS？

Question 1

base我相信如果您想覆盖 DNS 名称服务器，您只需在 .txt下的文件中添加与此类似的行即可resolv.conf.d。

例子

笔记：在开始之前，请确保安装了以下软件包，apt install resolvconf.

$ sudo vim /etc/resolvconf/resolv.conf.d/base

然后将您的名称服务器列表放入如下所示：

nameserver 8.8.8.8
nameserver 8.8.4.4

最后更新resolvconf：

$ sudo resolvconf -u

如果您查看手册页，resolvconf它描述了/etc/resolvconf/resolv.conf.d/.

   /etc/resolvconf/resolv.conf.d/base
          File  containing  basic  resolver  information.  The lines in this 
          file are included in the resolver configuration file even when no
          interfaces are configured.

   /etc/resolvconf/resolv.conf.d/head
          File to be prepended to the dynamically generated resolver 
          configuration file.  Normally this is just a comment line.

   /etc/resolvconf/resolv.conf.d/tail
          File to be appended to the dynamically generated resolver 
          configuration file.  To append nothing, make this  an  empty  
          file.   This file is a good place to put a resolver options line 
          if one is needed, e.g.,

              options inet6

即使文件顶部有警告head：

$ cat /etc/resolvconf/resolv.conf.d/head
# 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

此警告的存在是为了在构建这些文件时，警告最终将进入resolv.conf这些文件将用于生成的结果文件中。因此，您也可以轻松地将nameserver上述文件中的行添加base到该head文件中。

参考

Answer

base我相信如果您想覆盖 DNS 名称服务器，您只需在 .txt下的文件中添加与此类似的行即可resolv.conf.d。

例子

笔记：在开始之前，请确保安装了以下软件包，apt install resolvconf.

$ sudo vim /etc/resolvconf/resolv.conf.d/base

然后将您的名称服务器列表放入如下所示：

nameserver 8.8.8.8
nameserver 8.8.4.4

最后更新resolvconf：

$ sudo resolvconf -u

如果您查看手册页，resolvconf它描述了/etc/resolvconf/resolv.conf.d/.

   /etc/resolvconf/resolv.conf.d/base
          File  containing  basic  resolver  information.  The lines in this 
          file are included in the resolver configuration file even when no
          interfaces are configured.

   /etc/resolvconf/resolv.conf.d/head
          File to be prepended to the dynamically generated resolver 
          configuration file.  Normally this is just a comment line.

   /etc/resolvconf/resolv.conf.d/tail
          File to be appended to the dynamically generated resolver 
          configuration file.  To append nothing, make this  an  empty  
          file.   This file is a good place to put a resolver options line 
          if one is needed, e.g.,

              options inet6

即使文件顶部有警告head：

$ cat /etc/resolvconf/resolv.conf.d/head
# 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

此警告的存在是为了在构建这些文件时，警告最终将进入resolv.conf这些文件将用于生成的结果文件中。因此，您也可以轻松地将nameserver上述文件中的行添加base到该head文件中。

参考

Question 2

我也对这个问题感兴趣，我尝试了@sim提出的解决方案。

为了测试它，我把

nameserver 8.8.8.8

在/etc/resolvconf/resolv.conf.d/base和

nameserver 8.8.4.4

在/etc/resolvconf/resolv.conf.d/head

然后我重新启动网络

sudo service network-manager restart

结果/etc/resolv.conf看起来像

# 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 8.8.4.4
nameserver 127.0.1.1

并nm-tool指出 dns 服务器是

DNS:             208.67.222.222
DNS:             208.67.220.220

这是我的路由器提供的。另一方面，挖掘地址表明

;; Query time: 28 msec
;; SERVER: 8.8.4.4#53(8.8.4.4)

如果我是对的，我从这一切中得出的结论是

resolvonf 仅读取“head”部分：“base”部分以某种方式由 dnsmasq 控制
无论 dhcp 提供的服务器如何，dnsserver 实际上都被强制为 8.8.4.4，但是您会失去 dnsmasq 提供的缓存，因为请求始终发送到 8.8.4.4
dnsmasq 仍然仅使用 dhcp 提供的 dnsserver。

总而言之，它有效，但我认为这不是所要求的预期结果。我认为更接近的解决方案如下。编辑

sudo vim /etc/dhcp/dhclient.conf

然后加

supersede domain-name-servers 8.8.8.8;

结果如下：resolv.conf仅包含127.0.0.1，这意味着调用了dnsmasq缓存并且nm-tool说

DNS:             8.8.8.8

这意味着如果搜索的名称不在缓存中，则在 8.8.8.8 上请求，而不是在 dhcp 提供的服务器上请求。

另一个（也许更好）选项是使用“prepend”而不是“supersede”：这样，如果 8.8.8.8 未解析该名称，则请求将回退到其他服务器。事实上，nm-tool 说

DNS:             8.8.8.8    
DNS:             208.67.222.222
DNS:             208.67.220.220

Answer