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English Forums => General Discussion => Topic started by: ricksense on December 04, 2025, 03:55:50 PM

Title: Unbound strange behavior
Post by: ricksense on December 04, 2025, 03:55:50 PM
 Hi,

OPNsense 25.7.8 runs as a VM in my Proxmox machine. I ran across a strange behavior of Unbound: my hosts behind OPNsense still have internet access and get their DNS queries resolved by Unbound if I simply uses the browser, but if I ping a website, say, google.com in the prompt command it doesn't get resolved.

I saw the logs in Reporting: Unbound DNS, and noticed that the requests from the hosts got dropped:

(https://images2.imgbox.com/db/01/TNEqBiiF_o.jpg) (https://imgbox.com/TNEqBiiF)

 Could you please help understand why it happens and how to fix it?

Thanks
Title: Re: Unbound strange behavior
Post by: Patrick M. Hausen on December 04, 2025, 04:41:04 PM
Probably local resolution fails entirely. You need to investigate the logfiles to find the cause of that SERVFAIL.

Your browsers continue to work because modern browsers implement their own methods of name resolution.
Title: Re: Unbound strange behavior
Post by: ricksense on December 04, 2025, 04:43:06 PM
Quote from: Patrick M. Hausen on December 04, 2025, 04:41:04 PMProbably local resolution fails entirely. You need to investigate the logfiles to find the cause of that SERVFAIL.

Your browsers continue to work because modern browsers implement their own methods of name resolution.

Yes, I found out that I can browser websites via Firefoxr because I had cloudflare DOT activatet on it.
But if I disabled it, I have the same problem. So, there is definitely something wrong with the DNS requests to Unbound.
But what exactly?

Thanks
Title: Re: Unbound strange behavior
Post by: Patrick M. Hausen on December 04, 2025, 04:45:17 PM
As I wrote: investigate the cause of the SERVFAIL by looking at the log files.
Title: Re: Unbound strange behavior
Post by: ricksense on December 04, 2025, 04:50:00 PM
Quote from: Patrick M. Hausen on December 04, 2025, 04:45:17 PMAs I wrote: investigate the cause of the SERVFAIL by looking at the log files.

If I set "Use System Nameservers" in the Query Forwarding settings, it works but I don't think Unboud is working properly this way.
Thanks
Title: Re: Unbound strange behavior
Post by: Patrick M. Hausen on December 04, 2025, 05:13:37 PM
Look at the Unbound log files for the cause of the SERVFAIL - how often do I need to repeat this?
Title: Re: Unbound strange behavior
Post by: ricksense on December 05, 2025, 01:49:43 PM
Quote from: Patrick M. Hausen on December 04, 2025, 05:13:37 PMLook at the Unbound log files for the cause of the SERVFAIL - how often do I need to repeat this?

I looked at both the Unbound log files and the firewall log. There is nothing meaningful. Even no log entries in the Unbound log files. The firewall lets queries PASS.

Thanks
Title: Re: Unbound strange behavior
Post by: Patrick M. Hausen on December 05, 2025, 01:57:42 PM
Then probably enable:

Services > Unbound DNS > Advanced > Log SERVFAIL
Title: Re: Unbound strange behavior
Post by: ricksense on December 05, 2025, 02:41:15 PM
Quote from: Patrick M. Hausen on Today at 01:57:42 PMThen probably enable:

Services > Unbound DNS > Advanced > Log SERVFAIL

Ok, I can see something as I ran a query:
Quote from: Patrick M. Hausen on Today at 01:57:42 PMThen probably enable:

Services > Unbound DNS > Advanced > Log SERVFAIL

Ok, I started seeing something as I ran a query:

(https://images2.imgbox.com/44/7a/4bgCVTjw_o.jpg) (https://imgbox.com/4bgCVTjw)

Thanks



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