MAC address

jc94062

Does anyone know of any way to grab a users MAC address with PHP?

I can't find any documentation about it at the PHP site.

Thanks

brandonschnell

if you're on the same local ethernet segment you can use arp to find out (get $REMOTE_IP & see if the arp cache has a match). but thats about it.

jc94062

Hmmm, ok, thanks.
Maybe something they'll think about for PHP5.

brandonschnell

its something that will likely never be added into any server scripting language used over the internet.

if you must have it, consider having the user download a natively compiled program that grabs the MAC address from the nic and sends it to you via email or GET to a web page.

jc94062

Hmmm, why is it likely to never be available?
I know things like PacketBoy take it...

Its not really really needed, just would be useful to verify / ban users.

brandonschnell

yes, but PacketBoy is a sniffer that scans traffic on the LOCAL ethernet segment.

according to rfc1180:
"The ARP table is necessary because the IP address and Ethernet
address are selected independently; you can not use an algorithm to
translate IP address to Ethernet address."

http://www.faqs.org/rfcs/rfc1180.html

and if you look at the rfc that defines tcp, rfc793, you'll find that the MAC address isn't defined in the headers.

http://www.faqs.org/rfcs/rfc793.html

thats why ARP is necessary. on a local ethernet segment arp is used to find MAC addresses based on an ip address.

simply put, tcp doesn't give us the MAC address for remote users. if tcp doesn't support this, then what you want can only be done if tcp is rewritten.