You can get the mac addresses and IP addresses together - have a look at this:
Retrieving IP and MAC addresses for a LAN[
^]
But that is a very clumsy solution.
Can I suggest that either they access via the PC name, or get the IP from the PC name? The latter is really simple:
IPHostEntry host = Dns.GetHostByName("ANAS");
IPAddress ipaddr = host.AddressList[0];
That way, it's not tied to hardware - which can break, it's not tied to a specific machine - which can be replaced. You don't need to change software, just set the appropriate PC Id.