Timeouts over UDP

[tbleiker]

Prerequisites

• [X] I have checked the Wiki and Discussions and found no answer

• [X] I have searched other issues and found no duplicates

• [X] I want to report a bug and not ask a question or ask for help

• [X] I have set up AdGuard Home correctly and configured clients to use it. (Use the Discussions for help with installing and configuring clients.)

Platform (OS and CPU architecture)

Linux, AMD64 (aka x86_64)

Installation

Docker

Setup

On one machine

AdGuard Home version

v0.107.43

Action

For some time now, I struggle with slow internet. I finally found time to look into the problem and found out that I often get timeouts when resolving over UDP. Interestingly, there are no timeouts when resolving over TCP (nslookup -vc ...) .

~> nslookup www.gmail.com
;; communications error to 192.168.2.50#53: timed out
Server:         192.168.2.50
Address:        192.168.2.50#53

Non-authoritative answer:
Name:   www.gmail.com
Address: 216.58.215.229
Name:   www.gmail.com
Address: 2607:f8b0:400f:807::2005

Interesting as well: On the server itself (where the docker image is running), there are no timeouts with nslookup www.gmail.com localhost but with nslookup www.gmail.com 192.168.2.50.

I am back now on v0.107.29 and everything is working again. I can't tell if this is the last version without this problem. I currently don't have the time for more trial and error... 😀

Expected result

No timeouts when resolving over UDP (see above).

Actual result

Timeouts when resolving over UDP (see above).

Additional information and/or screenshots

Used port mapping: -p 53:53/tcp -p 53:53/udp

[ainar-g]

Interesting as well: On the server itself (where the docker image is running), there are no timeouts with nslookup www.gmail.com localhost but with nslookup www.gmail.com 192.168.2.50.

Unless you're running with --net=host, it probably just means that the IP is different from within your container.

You can enable verbose logs to see if there are any UDP warnings or errors. Another useful thing is to use dig instead of nslookup, since it reports errors like bad source address much better.

[tbleiker]

I am running without --net=host. But I tested with it as well - same outcome... I might test with verbose output when I find more time.

I stopped digging deeper because it perfectly works with an older version. I am wondering what changed...