How to detect what connections a software / application is trying to make

[itsnotsaved]

I have AdGuardHome installed and multiple devices connected to it. One device try to keep connect to specific domain continuously that already blocked but i dont know how to detect which application is trying for connect to that domain. Basically i tried to detect by closing applications and netstat tool doesn't help. (In debian based distro)

[ameshkov]

Not an easy thing to do considering that the app probably uses getaddrinfo and the DNS query is sent by the system.

You probably need to:

1. Unblock that domain or use $dnsrewrite to point it to some real IP address
2. Use netstat and look for connections that that IP address to find the process