Hello,
I am getting the following error: Connection error (**2606:4700:4700::1111#53** ): failed to send UDP request (**Network unreachable** )
I am using CloudFlare as DNS - no custom name servers.
How do I resolve this one?
How is your Pi-hole connected to your network? It (briefly) lost connection and, hence, the corresponding packet could not be sent upstream.
This does happen every now and then for Wi-Fi connections, getting significantly worse with weak signal strength (larger distance to the router). It can of course also happen with wired connections, in which case the entire upstream internet connectivity might have briefly been down. In case of the latter, there isn't much you can do but your Pi-hole still makes you aware of it. In case it happens often you will have to contact your internet service provider (ISP).
I just upgraded to v6 and am now getting this error as well
Connection error (2606:4700:4700::1111#53 ): failed to send UDP request (Network unreachable )
1 Like
Getting the same error after the update. Happens while using 9.9.9.11 also.
1 Like
I am also seeing this after updating from the latest v5 to v6.
1 Like
I’m getting the same error after upgrade to v6 as well.
Same here, I do not allow UDP out though if it matters: Did not get this with 5.X
2025-02-18 20:53:52 CONNECTION_ERROR Connection error (**2a0d:2a00:1::1#53**): failed to send UDP request (**Network unreachable**)
I see nextdns dns server entry in the warning logs as well see below. I use their dns service.
Log:
2025-02-18 20:18:17.647 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:18:18.650 ERROR add_message(type=12, message=2a0d:2a00:1::1#53) - SQL error step DELETE: database is locked
2025-02-18 20:18:18.650 ERROR Error while trying to close database: database is locked
2025-02-18 20:19:04.853 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:20:38.113 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:23:07.072 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:25:31.055 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:25:39.880 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:25:45.965 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:27:29.645 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:28:27.846 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:28:42.635 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:29:43.501 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:32:05.376 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:33:55.095 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:34:28.344 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:34:39.092 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:34:58.810 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:36:32.580 WARNING Connection error (45.90.28.208#53): failed to send UDP request (Network unreachable)
2025-02-18 20:36:58.448 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:37:26.528 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:38:28.179 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:40:00.714 WARNING Connection error (2a0d:2a00:1::1#53): failed to send UDP request (Network unreachable)
2025-02-18 20:40:01.717 ERROR add_message(type=12, message=2a0d:2a00:1::1#53) - SQL error step DELETE: database is locked
I'm in exactly the same situation after updating to version 6.
I think I discovered the issue on my end. I don’t have IPv6 enabled on my router but I did have the IPv6 upstream DNS servers enabled. After turning them off, the error went away and hasn’t come back.
3 Likes
Same error here after update from last 5.x to 6.0.
After switching ipv6 on some DNS-Providers on and off, the error is still there with every DNS-Provider.
With 5.x I never saw this error and I changed nothing beside the update.
Everything else is working fine.
I removed my IP6 address and thought that fixed it, but now it is showing the same error to my custom IP4 DNS servers. So it just moved the issue, if it is an issue.
I also get this error message after upgrading to v6
Also getting this error on my piholes after the v6 upgrade. Both hardwired on the same network. One getting errors, the other isn’t interestingly.
IPv6 works just fine.
Work
This warning is new in v6, the issue has most likely been there before, you just never noticed. Most (if not everyone) is having intermittent Internet outages (or just badly chose routes, they change all the time!) and packets get lost. Usually, the web servers are using TCP which has an in-built retransmission mechanism for exactly this usecase, UDP just doesn't have it. You probably still don't know about this as the original requestor will just re-query after a timeout of maybe two seconds and this time it will work.
Hence, a question for you guys: Looking at /var/log/pihole/FTL.log - how often do you see this? If it happens only a few times an hour, it is nothing to be worried about at all. If it happens like thousands of times per minute, this is more real of an issue.
I think we somehow need to make this warning less obvious to avoid users reading to much into it. I was thinking about maybe a threshold, only putting up the warning if we have seen more than, say, 10 of them in the last minute. Any objections/suggestions? Picking this threshold also depends on your feedback concerning the frequency in your log files.
5 Likes
I think that’s a great idea. Setting a threshold would definitely make this less intrusive. I seem to only be getting it one or two times a day, but the notification is there.
This error occurs for me too. I'm using the docker container of pihole, and the errors appear in the Container log rather than in /var/log/pihole/FTL.log. I've analyzed my logs from the past 12 hours:
- During quiet periods (when I was not home), errors occur roughly every 7-14 minutes
- During active usage, errors can occur up to 4 times per minute
- The shortest interval between errors was 6 seconds, while the longest was about 14 minutes
From what I see in my logs, a threshold of 10 errors per minute seems reasonable - it would filter out the normal background errors while still alerting on significant connectivity issues.
Edit: I have attached the logs filtered for 'Network unreachable' for inspection.
pihole_logs_unreachable.txt (17,1 KB)
Please try
sudo pihole checkout ftl tweak/conn_errors_threashold
for an implementation with a threshold.
Gave it a shot on pi #2 and it hangs in downloading and installing FTL. I’ll give it another try tomorrow.
i have the same error. The error occurs if my internet provides starts the internet forced separation. In this time the connection is lost for some seconds.