Fixing Search Domain Resolving on WSL

10/27/2017 • 2 minute read

I have recently been playing with Microsoft’s newest attempt at “embrace, extend, and extinguish” called Windows Subsystem for Linux (WSL).

I can’t really give a fair review yet as one the first issues I ran into is its broken DNS setup. After doing some searching, it appears to be related to the fact that WSL can’t properly move over multiple Search domains into your Linux’s /etc/resolv.conf, a common setup in enterprise environments or VPN setups.

Microsoft is aware of this issue but doesn’t seem able/willing to fix it, so here is a workaround:

On your WSL prompt, make a copy of your existing /etc/resolv.conf
```
$ sudo cp /etc/resolv.conf /etc/resolv.conf.new
```
Unlink the existing /etc/resolv.conf
```
$ sudo unlink /etc/resolv.conf
```

Move the copied version back

$ sudo mv /etc/resolv.conf.new /etc/resolv.conf

Delete the first line in the file mentioning WSL auto-generation using your text editor or:
```
$ sed -i '1d' /etc/resolv.conf
```

Now on a Windows Command Prompt, run the following:

> ipconfig /all

and you should get an output like this:

Windows IP Configuration

Host Name . . . . . . . . . . . . : hostname
Primary Dns Suffix  . . . . . . . : example.com
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : example1.com
                                    example2.com
                                    example3.com
                                    example4.com
                                    example5.com
                                    example6.com

Mark down the Search List section. The more tool is helpful if you have a lot of information to scroll through.

Add the Search List to your /etc/resolv.conf. It should look something like this at the end of your file:
```
search example1.com example2.com example3.com example4.com example5.com example6.com
```
Place all your Search Domains on one line with the word “search” at the start. You can have up to 6 domains.

Now save your /etc/resolv.conf and you should be good to go!

Fixing Search Domain Resolving on WSL

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