Question : How can  I setup a PHP socket connection using MAC address instead of IP address?

I need to communicate with several (25-50) specialized devices from a PHP-based webpage. I have a working prototype which uses socket_connect, but that approach requires me to know the IP address of the device.

My client wants to let DHCP assign the device IP addresses so he doesn't have to keep track of static IP addresses.

Is there a way in PHP to find the current IP address for a specific MAC address?

Alternately, I can broadcast a command for all devices on the network to send me their MAC address. Is there a way in PHP to extract the IP address from the Ethernet packet the devices send me?

(I know this can be done in VB, so there SHOULD be a way in PHP)

Answer : How can  I setup a PHP socket connection using MAC address instead of IP address?

I've given up on this idea.

I never found a way to make it work, but even if I eventually did, it would be so "non-standard" (nice way to say "kludgy") that I wouldn't want to rely on it.

I've talked my client into using static IP addresses assigned to the devices at installation. That way I can use sockets they way they were designed to be used.

I consider this question closed, but I don't know how to close it without awarding points.