Question about Hostname and DNS client on Debian 12

Debian 12
Webmin version 2.105


In “Hostname and DNS client” under “Resolution order” I have the following error:

files resolve [!UNAVAIL=return] dns

It seems that I have this on all Debian 12 servers, just purchased and installed fresh ! Any idea of what might cause this ? I have a possible consequence in Nextcloud where I’m getting an error about not being able to resolve “/.well-known/caldav”, it’s my first install of NC on D12+Virtualmin, I’ve got at least 10 others on D11 not having that error so I’m starting to think this could be related …
If somebody has an idea :slight_smile:


In fact this comes from /etc/nsswitch.conf, I replaced:

hosts: files resolve [!UNAVAIL=return] dns
hosts: files dns

“Hostname and DNS client” under “Resolution order” is back to normal in Virtualmin. I have this in all my debian12 servers, looks like something is not working properly generating that “resolve [!UNAVAIL=return]”, not sure I had to remove “resolve”, in fact i copied from an existing and working debian 11 nsswitch.conf .


It seems that I have this on all Debian 12 servers, just purchased and installed fresh!

It is a valid string. You shouldn’t worry about it. Although, we don’t provide a nice way to edit it (yet) but it’s possible to edit it directly using textbox.

Any idea of what might cause this ?

The hosts: entry in /etc/nsswitch.conf determines the order in which the system resolves hostnames to IP addresses.

  • hosts:: This indicates the beginning of the configuration for hostname resolution.
  • files: This tells the system to first look in the local files for hostname resolution, which on most Unix-like systems refers to the /etc/hosts file.
  • resolve [!UNAVAIL=return] : This specifies the use of the systemd-resolved service. The [!UNAVAIL=return] part is a conditional statement that says if the resolve source is not available, then return immediately without proceeding to the next sources.
  • dns : This indicates that if the previous sources (files and potentially resolve ) did not successfully resolve the hostname, the system should use the Domain Name System (DNS) servers specified in the /etc/resolv.conf file or other DNS configuration.
1 Like

@Ilia in debain 11 and 12 i see a issue

I get errors like Failed to create active route : SIOCADDRT: No such device and SIOCADDRT: No such device

I cant see any network interface and i also not being able to delete the network routes but i am able to delete default route. Why?

What is Network config type set to in table header in main Networking ⇾ Network Configuration page?

Here it is
OS: Debain 11
Network Config Type: Debain Linux

What is the content of /etc/sysctl.conf and /etc/network/interfaces files on your system?

I sent you message sir because that contains some sensitive information. please check it. Thankyou

Ok thanks, so I understand that this string is “normal”, it’s just Virtualmin not providing a nice way to edit it. Is removing it a problem ? I don’t have resolve [!UNAVAIL=return] in Debian 11 servers, I guess this a new Debian 12 feature ?

I think its better to just leave it as it is if you dont know what you are doing :slight_smile: and you understood it right ‘’‘That this string is “normal”, it’s just Webmin not providing a nice way to edit it.’