DNS resolution stopped working after Windows 11 22H2

[ceecko]

Version

Microsoft Windows [Version 10.0.22621.521]

WSL Version

• WSL 2
• WSL 1

Kernel Version

5.10.102.1-microsoft-standard-WSL2

Distro Version

Ubuntu 20.04

Other Software

No response

Repro Steps

WSL cannot reach the defined nameserver after upgrade to Windows 11 22H2.
Ping to the nameserver does not work.

Expected Behavior

DNS resolution shall work.
It worked before upgrade to Windows 11 22H2.

Actual Behavior

$ cat /etc/resolv.conf
# This file was automatically generated by WSL. To stop automatic generation of this file, add the following entry to /etc/wsl.conf:
# [network]
# generateResolvConf = false
nameserver 172.25.0.1

$ ping 172.25.0.1
PING 172.25.0.1 (172.25.0.1) 56(84) bytes of data.
^C
--- 172.25.0.1 ping statistics ---
12 packets transmitted, 0 received, 100% packet loss, time 11443ms

Diagnostic Logs

Networking works ok

$ ping 1.1.1.1
PING 1.1.1.1 (1.1.1.1) 56(84) bytes of data.
64 bytes from 1.1.1.1: icmp_seq=1 ttl=58 time=9.26 ms
^C
--- 1.1.1.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 9.256/9.256/9.256/0.000 ms

[Loccko]

Have the same problem after update, well done Ms.....
As an TEMPORARY solution:

1. sudo nano /etc/resolv.conf
2. Remove line out the nameserver nameserver 17...
3. add this new line nameserver 8.8.8.8
4. ctrl + o and ctrl + x to write a quit
5. sudo nano /etc/wsl.conf
6. Paste the following in:

[network]
generateResolvConf = false

7. ctrl + o and ctrl + x to write a quit
8. close WSL and reopen

Thanks to yebocal #5336 (comment)

[ceecko]

This was an issue with ESET Internet Security.
Firewall started blocking the traffic.

You can reconfigure the firewall and DNS starts working again.

[RiccardoManzan]

@ceecko , i have not ESET internet security, then i guess that is not the issue.
Anyway yeah i guess that some sort of windows firewall rule has been changed during 22h2 update which broke dns resolution for hyper-v machines and WSL.
Could you be more specific on what we should reconfigure on windows firewall in order to make the DNS reachable again?

[michal-kralik]

Not sure about your setup but I had to whitelist the subnet used by WSL