connecting to a listening device

Hi, I am trying to develop an application as follows:

I have a pc and a laptop, I want the laptop to always be listening for an incoming connection from the pc, however the pc doesn't know the laptops IP address to connect to. Is there a way for the pc to connect to any listening laptop, and once connected then check a database that I have that has a list of MAC addresses, and if the MAC address of the laptop is there then the connection stays open, otherwise it is shut???

Many thanks

You can get the IP address of any machine on your network as long as you know its machine name.