Re: MAC Address

The MAC address is not unique for each card, it is supposed to be but hardware hardware manufacturers ran out of unique mac addresses some time ago. They are now re-using mac addresses with the knowledge that the liklihood of the same MAC making its way onto the same LAN is extremely low. The MAC is a local area network hardware identificater for local area network use, not for the Internet. Even if you could get the MAC you shouldn't use it as a unique identifier because most operating systems let you change your mac to whatever mac you want (software vs burned in MAC). You should find another way to uniquely identify the computer, consider using client side SSL certificates. Chris Hewitt wrote:

Urb LeJeune wrote:

oh dear i'd like to know this too , as getting an ip is quite tedious if the proxy blocks it

        Just a little background. The MAC address is unique for each

computer. Would be perfect to determine if a user has already voted in a poll or something like that. Much more reliable indicator than an IP address. Microsoft is now using the MAC address when issuing passwords for installing software.

The MAC address is unique for each ethernet card, is there an equivalent for e.g. a serial dial-up interface? Change the network card (or buy a new computer) and you have a different MAC address. HTH Chris