Re: Envairoment variables

George your answer is most valuable, thanks. ----- Original Message ----- From: "George Schlossnagle" <george@omniti.com> To: "Ivan Rodriguez" <epplestun@alaplaya.com> Cc: "Derick Rethans" <derick@php.net>; "Filip de Waard" <dewaard@netcollective.nl>; "php-dev" <internals@lists.php.net> Sent: Thursday, October 30, 2003 4:52 PM Subject: Re: [PHP-DEV] Envairoment variables > > On Thursday, October 30, 2003, at 10:41 AM, Ivan Rodriguez wrote: > > > Ok, But if the REMOTE_ADDR is part of the client and it gives back a > > PHP > > variable to it, it is not possible to do the same with the MAC address. > > IP addresses are machine identifiers in IP, so when someone makes an > http connection to you, you two establish a TCP/IP session and thus you > need to know the remote server IP address to make it work at all. > > MAC addresses are part of the lower level ethernet protocol, and serve > as a way of direct neighbors (folks on the same ethernet segment) to > know who each other are. Thus, when you have a connection that crosses > any sort of network routing device (anything that does more than simply > forward packets), the MAC address does not get propogated. This is > simply 'The Way Things Work' (tm), and their is no changing it. > > Of course a machine knows it's own MAC and a browser can set any header > field it want, but deciding what to send is up to the browser, not up > to PHP. I don't know of any browser that sends it's MAC address, but > regardless that is something that's up to the browser vendors, not PHP. > > We understand what you are trying to do and you can't do it. > > George >