Pihole in a docker container don’t resolve local ips #part2, now receive NXDOMAIN

[Loris_Verga]

Hi all!
Following my last post: Pihole in a docker container don't resolve local ips

Now (i don't know why) stopped working and give me this for every local pc:

nslookup lnxsrv
Server: 192.168.188.100
Address: 192.168.188.100#53
** server can't find lnxsrv: NXDOMAIN

I've just upload a debug log https://tricorder.pi-hole.net/IYTHBdiE/
Please

[Bucking_Horn]

Let's query your router for that name, just as Conditional Forwarding would do.
What's the result of:

nslookup lnxsrv 192.168.188.1

[Loris_Verga]

nslookup lnxsrv 192.168.188.1
Server: 192.168.188.1
Address: 192.168.188.1#53

** server can't find lnxsrv: NXDOMAIN

[Bucking_Horn]

Pi-hole just returns your router's reply, so that confirms that it is your router that does not know a client by that name.

Why do you expect that name to resolve to an IP?
Which IP did you expect?

[Loris_Verga]

I don't know why, but my lnxsrv is listed as "ubuntu" in the fritbox UI:

But the hostname is lnxsrv, in etc/hosts and etc/hostname

Where he find "ubuntu" that's is not ubuntu but debian 12?

Manual changed on the FritzUI in knxsrv and now, it's working.
@Bucking_Horn you are my hero

[Bucking_Horn]

@Loris_Verga

Where he find "ubuntu" that's is not ubuntu but debian 12?

That's a question for your router's manufacturer.
Perhaps if you did use the same MAC or IP with a different name in the past, your FritzBox router may hold on to that previous name, instead of or in addition to the current ubuntu.

Before you adjust the name via FritzBox's UI, try if querying the FritzBox for known names for that IP would return more than one name:

dig -x 192.168.188.100 @192.168.188.1

[Loris_Verga]

Now i have understand.
This morning i'va booted up lnxsrv with a Rescuezilla usbkey to do a backup.
The router must have taken the name at that time and, having the same ip, on reboot it no longer changed it to lnxsrv.

Thanks again!