If the configured ip-address is listening for incoming debug connections it will respond with further commands to facilitate the debugging session.

When you look at it, the concept of Xdebug is actually rather simple: whenever a PHP with Xdebug is triggered to start a session, Xdebug will send a initialization packet towards the configured remote_connect_back ip-address in the configuration. It mostly boils down to the same things over and over again, albeit in different scenario’s. This is because debugging actually isn’t that hard to configure and use once you get the hang of it. When reading the chapters below, you’ll find that there is a recurring theme of “configuring the xdebug module”, “enabling your IDE to listen on the configured port” and “initiating a debug session”. Using debuggers in PHP is probably no unfamiliar territory for us developers, but do you know how to set-up Xdebug for your CLI script? Or perhaps you are experimenting with containers and resorted back to using the good old `dd()` or `var_dump()` because the extra twist in the Docker network made your old Xdebug configuration ineffective? No worries: We’ve hooked you up with a small handbook you can use in the most common PHP debugging situations this year.

Phpstorm 2018