DNS无法被Tailscale自动修改/ DNS Unchanged After Installation

• 情况一

一般比较容易出现在Ubuntu及较高版本的Debian系统

原因是系统自带systemd-resolved的DNS服务器占用了53端口。需要手动卸载该服务并指定Tailscale的DNS。

以下为具体步骤：

1. 检查系统是否带有systemd-resolved服务，apt install lsof && lsof -i:53

2. 如果53端口被systemd-resolved占用，则运行下面的命令：

3. systemctl disable systemd-resolved --now

4. rm /etc/resolv.conf

5. echo "nameserver 100.100.100.100" > /etc/resolv.conf

• 情况二

如果系统中的53端口并没有被其他程序占用，您可以简单地重启tailscale并查看系统DNS是否有被修改成100.100.100.100

• tailscale down && tailscale up

• cat /etc/resolv.conf

如果此时系统DNS仍非100.100.100.100，您可以手动修改系统DNS

• echo "nameserver 100.100.100.100" > /etc/resolv.conf

DNS Cannot Be Automatically Modified by Tailscale

Scenario 1

This issue often occurs on Ubuntu or newer versions of Debian systems.

Cause: The system’s built-in systemd-resolved DNS service occupies port 53. You need to manually disable this service and specify Tailscale’s DNS.

Steps:

1. Check whether the system has the systemd-resolved service:

   apt install lsof && lsof -i:53

2. If port 53 is occupied by systemd-resolved, run the following commands:

   systemctl disable systemd-resolved --now

3. Remove the existing DNS configuration file:

   rm /etc/resolv.conf

4. Add Tailscale’s DNS configuration:

   echo "nameserver 100.100.100.100" > /etc/resolv.conf

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Scenario 2

If port 53 is not occupied by any process, you can simply restart Tailscale to check whether the system DNS has been changed to 100.100.100.100:

tailscale down && tailscale up  
cat /etc/resolv.conf

If your system DNS is still not 100.100.100.100, you can manually modify it:

echo "nameserver 100.100.100.100" > /etc/resolv.conf