QUESTION: Not picking up host names

[holocronology]

I'm not sure if this is a bug or likely a configuration issue.

My network router is running bare metal OPNsense. Most of my devices have static IP and hostnames defined in the DHCPv4 server.

My DNS is configured as AdGuard Home (on Proxmox) > Unbound DNS > Out to DNSoverTLS servers.

I'm running this installation of Pi.Alert on the same Proxmox server as AdGuard Home. I'm not sure what changed, but since the last update I am not getting any hostname data. Previously it would autopopulate with the hostnames from my routers.

Now I see:

or

Note that 10.10.0.57 is my AdGuard instance--aka primary DNS.

[leiweibau]

If it worked before, maybe the sourcery optimization broke something. I will undo this.

[leiweibau]

What happens, when you run the command dig +short -x ONE_UNKNOWN_HOST_IPwith the IP of one for the (unknown) hosts instead of ONE_UNKNOWN_HOST_IP? Do you get an error or a hostname?

[holocronology]

dig +short -x ONE_UNKNOWN_HOST_IP

I get no response running it on the shell of the LXC or the host.

[leiweibau]

That is a sad. With this command, the backend tries to determine hostnames that it has not yet been able to determine using other methods. Do you have the possibility to install "avahi-utils" in the container and then execute the command avahi-resolve -a ONE_UNKNOWN_HOST_IP (replace ONE_UNKNOWN_HOST_IP with an IP of an unknown host)? Or for example avahi-resolve -a 10.10.0.57.

[leiweibau]

what happens when you modify the command to dig +short -x ONE_UNKNOWN_HOST_IP @10.10.0.57 (replace ONE_UNKNOWN_HOST_IP with an IP of an unknown host)?

[holocronology]

[holocronology]

I don't know if this is helpful.

I have a printer on my local network that has a host name assigned to it on my OPNsense router with a static IP. So, even without something like NPM set up, it will resolve from hostname.localnet.net to the correct address.

The above is from inside the command shell of the pi.alert lxc.

I wonder if Pi.Alert is getting tripped up because when AdGuard processes and then forwards to the upstream DNS server (Unbound DNS on my OPNsense router) it does so on port 65353 and my firewall is set up to allow DNS on the LAN on that port.

[leiweibau]

At that moment, your DNS simply does not seem to have a hostname for this IP. In addition to "dig", I have added "avahi-resolve" as a source for determining the host name and also created the option to explicitly specify a DNS server in the configuration that is to be used for name resolution, as with the command "dig +short -x ONE_UNKNOWN_HOST_IP @10.10.0.57"

Have you tried to install the avahi-utils and test for example avahi-resolve -a 10.10.0.80?

If Adguard uses an upstream DNS for name lookup, how is upstream DNS supposed to recognize your hostname? Is Adguard your only DNS server in the LAN?

[leiweibau]

I wonder if Pi.Alert is getting tripped up because when AdGuard processes and then forwards to the upstream DNS server (Unbound DNS on my OPNsense router) it does so on port 65353 and my firewall is set up to allow DNS on the LAN on that port.

As interesting as I find OPNsense or pfSense, I have no experience with them at the moment, so I can't help here.

[holocronology]

option to explicitly specify a DNS server in the configuration that is to be used for name resolution

I thought this might be the case but for some reason I was unable to find it. Let me check to see if that helps. I appreciate the assistance thus far.

[holocronology]

Is this what you were referring to?

[leiweibau]

Is this what you were referring to?

No. This entry is used to determine a rogue DHCP server.

The configuration option I am referring to has not yet been published, as I only run such things for a few days to see if there could be any problems. I am referring to this commits in the "next_update" branch https://github.com/leiweibau/Pi.Alert/commit/27800d3a398cadfc1fd0296075ba22759510c16b, https://github.com/leiweibau/Pi.Alert/commit/ad1ab0aca1c8e8fce9fb40e3a6b7eee53c8711ae, https://github.com/leiweibau/Pi.Alert/commit/7ba156f184374b7b5f0d83e4b701f6623f47d40c, https://github.com/leiweibau/Pi.Alert/commit/cea08ecb06574c4ba28e72d0e3ad22fdf9fc5f36

[leiweibau]

I have added 2 more methods for hostname detection (mDNS and Netbios). It is important that Pi.Alert gets through the firewall to be able to query these protocols. The same still applies to DNS, of course. If you create a DNS entry in your DNS server for each device in question, name resolution should no longer be a problem at all, as long as Pi.Alert can reach the DNS server.