I have Xdebug working with PhpStorm and all is good, however, when I'm debugging code it also runs a debug session for others using the server.
Is it possible to define an IP address or IP range for the debugger start and to ignore and just serve the page for other addresses?
You can not restrict it on IP address, but you can set up a shared secret in php.ini/xdebug.ini. Only the developer that uses the shared secret in their browser extension to activate the debugging session will then initiate a debugging request. If the wrong secret is present, it won't.