How do I get the IP address of a remote sockets device?

[bobdoss]

I have some specialized devices on my network that I can communicate with over a UDP sockets connection.

But first I need to get their IP addresses programmatically so I can "socket_connect" to them.

I can broadcast a command that will cause them to send me their MAC address, but their IP address is not in the packet payload they send me.

Is there any way in PHP to get the IP address from the packet header that carries the MAC address?

Any other ideas on how to get the remote IP addresses programmatically?