Local name resolution (mDNS) is not working with fresh install of WSL 2 on Windows 11

[solarslurpi]

Windows Version

Microsoft Windows [Version 10.0.22631.4541]

WSL Version

2.3.26.0

Are you using WSL 1 or WSL 2?

• WSL 2
• WSL 1

Kernel Version

Linux version 5.15.167.4-microsoft-standard-WSL2 (root@f9c826d3017f) (gcc (GCC) 11.2.0, GNU ld (GNU Binutils) 2.37) #1 SMP Tue Nov 5 00:21:55 UTC 2024

Distro Version

24.04

Other Software

On a fresh install of Windows 11 with WSL 2, local IP names ( e.g.: beanie.local) resolved correctly in PowerShell but not within WSL 2.

Steps Taken:

1. Works in PS not in WSL:

   • Attempted to ping beanie.local insode Powershell, ping succeeded.
   • Attempted to ping beanie.local inside WSL 2, but the ping failed.

2. Avahi Daemon - is this the problem?:

   • Installed and started avahi-daemon in WSL 2 to enable mDNS resolution.
   • Ran avahi-browse to check if the mDNS service was working, but the command hung and did not return any results.
   • Checked the avahi-daemon logs via journalctl and saw no errors during startup, but it didn't help with mDNS resolution in WSL 2.

3. Firewall Configuration - is this the problem?:

   • Attempted to enable mDNS by opening ports in Windows Firewall:
     • Inbound Port: Allowed UDP traffic on port 5353 for mDNS.
     • Outbound Port: Allowed outbound traffic on port 5353 for mDNS.
   • Despite these changes, mDNS resolution still didn’t work within WSL 2.

4. Manual Workaround - bummer...why is this so...frustrating?:

   • Edit /etc/hosts in WSL 2: As a workaround, manually added an entry for beanie.local in the WSL /etc/hosts file, mapping it to its IP address.
   • Configure /etc/wsl.conf: Adjusted DNS settings in /etc/wsl.conf to try to improve name resolution and restarted WSL after modifications.

5. Issue with mDNS Service in WSL 2:

   • Despite configuring avahi-daemon and adjusting firewall settings, mDNS still didn't resolve .local addresses within WSL 2.
   • The issue is that mDNS multicast packets are not natively supported in WSL 2, and avahi-daemon or similar services cannot fully resolve .local addresses.

Resolution:

While manual entries in /etc/hosts provided a workaround, the mDNS service didn't work as expected within WSL 2, even after opening the necessary ports. The firewall changes were tested (allowing inbound and outbound UDP traffic on port 5353), but they did not enable mDNS support in WSL 2.

Conclusion - Huh? Please help?:

The problem was temporarily fixed by:

• Editing /etc/hosts: Manually adding an entry for beanie.local in WSL 2's /etc/hosts file, mapping it to the correct IP address.
• **Editing /etc/wsl.conf: add the following entry to /etc/wsl.conf:

# [network]
# generateHosts = false

Request for Help on Stack Overflow:

Any advice on getting full mDNS support working inside WSL 2 would be greatly appreciated."

Repro Steps

see above..

Expected Behavior

ping beanie.local resolves without having to modify a hosts file. All locals just resolve.

Actual Behavior

ping beanie.local does nto resolve unless added to hosts file and 3 chickesn are spun clockwise over my head.

Diagnostic Logs

No response

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View similar issues

Please view the issues below to see if they solve your problem, and if the issue describes your problem please consider closing this one and thumbs upping the other issue to help us prioritize it!

Open similar issues:

• HOSTNAME.local: Name or service not known (#10077), similarity score: 0.78
• mDNS stopped working in WSL2 after Windows 11 Pro update (#11022), similarity score: 0.77
• Able to nslookup .local address but Unable to ping (#12224), similarity score: 0.74
• mDNS does not work with mirrored network mode (#11852), similarity score: 0.73

Closed similar issues:

• No name resolution in WSL2 even with custom resolv.conf (#6219), similarity score: 0.74

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[LakhveerChahal]

Facing the same issue, I have created a script to manually update etc/hosts and added it in .bashrc as an alias. This way whenever the ip changes for .local domain, I can update the etc/hosts file manually through command.

[CatalinFetoiu]

thanks for reporting the issue. can you please check if the documentation we have about mDNS resolution resolves your issue? (https://learn.microsoft.com/en-us/windows/wsl/troubleshooting#resolve-local-names-in-wsl)