I decided to give Windows another chance recently for a work project (rolling out Windows 11 actually) and wanted to get some sort of development environment setup on my computer. Specifically, the ability to continue to run bash scripts where I’m most comfortable. Unfortunately, at one point I got an error while trying to run git clone ssh:... - the error was ping: google.com: Temporary failure in name resolution.
After some googling, I saw some people talking about changing the /etc/wsl.conf file and resolver.conf and I thought no way, this is a fresh install of WSL2! But then one comments caught my eye about this only happening when a VPN was running. Aha! I have Cloudflare WARP running locally, which is essentially my VPN, but more importantly it hijacks my DNS to provide protection… I then tweaked my Google search (“cloudflare warp wsl2 temporary failure in name resolution) and that yielded the results I was expecting - a number of Cloudflare community posts. This is a common problem!
To ensure this was my issue, I tried to ping google.com with the Cloudflare WARP client enabled and it yielded the “Temporary failure in name resolution” issue. Once I toggled WARP off, ping worked again. After running cat /etc/resolv.conf, I see at the top it says it was automatically generated by WSL and I see the nameserver is set to 172.31.0.1. Funny enough, this route IS included in my Cloudflare WARP Split Tunnel “include” configuration. I imagine that my DNS requests are just being black holed, because that IP likely isn’t a DNS server (or anything) on my network that Cloudflare is tunneling through. I imagine most folks on the internet may be facing this issue as well, as they might be set to “Exclude” by default? Who knows? Also, this may not be my exact issue and just a coincidence, however I like to thing I’m this smart and have connected these dots :)
Understanding the Issue
WSL2 and Virtual Networking
WSL2 uses a virtual network that’s separate from the Windows network, and when Warp is connected, the WSL2 network might not automatically inherit the DNS settings.
resolv.conf: WSL2 typically manages the DNS configuration through the /etc/resolv.conf file, which is usually a symlink to a file managed by the WSL runtime.
Cloudflare Warp and DNS: When Warp is enabled, it uses its own DNS servers (1.1.1.1 and 1.0.0.1), and WSL2 needs to be configured to use these servers for name resolution.
To fix it
- Disable automatic
resolv.confgenerationsudo vim /etc/wsl.conf- Add or modify the following lines:
[network] generateResolvConf = false
- Shut down WSL from a separate command prompt (won’t work within WSL2 prompt)
wsl --shutdown
- Start WSL again
- If you had a terminal open, likely just hit Ctrl+D or Enter to start it up again or open a new terminal.
- Manually configure
resolve.conf- If you’ve disabled automatic generation, create a new
/etc/resolv.conffile with the following content (or update it if it already exists):nameserver 1.1.1.1 nameserver 1.0.0.1
- If you’ve disabled automatic generation, create a new
- Try to ping google.com again
ping google.com
- Confirm the file does not get removed after reboots:
sudo chattr +i /etc/resolv.conf
More resources
What would a post from me be without more information?