title: Why can't the server get the client MAC address, like the client IP?
body: <p>From what I know, all the MAC addresses that the packet gone through are in the packet. This is because that each packet that goes in a certain path, should also be returned in similar path. So, if the router of the server know about the mac address of the client (all of them), why the server page (like aspx) cannot have this information?</p>
  
  <p>Please, give an explanation. (don't just tell me that I'm wrong).</p>
  
  <p>If I understand it correctly, the client sends a packet that contains it's MAC address. when to packet go through a proxy (like the client router), the proxy's address is added to the packet too. and so on.</p>
  
  <p>Here is a snippet from Wikipedia about the TCP/IP data line layer:<br>
  <a href="http://en.wikipedia.org/wiki/TCP/IP_model#Data_Link_Layer" rel="noreferrer">http://en.wikipedia.org/wiki/TCP/IP_model#Data_Link_Layer</a></p>
  
  <blockquote>
    <p>The Data Link Layer is used to move
    packets between the Internet Layer
    interfaces of two different hosts on
    the same link. The processes of
    transmitting and receiving packets on
    a given link can be controlled both in
    the software device driver for the
    network card, as well as on firmware
    or specialized chipsets. These will
    perform data link functions such as
    adding a packet header to prepare it
    for transmission, then actually
    transmit the frame over a physical
    medium. The TCP/IP model includes
    specifications of translating the
    network addressing methods used in the
    Internet Protocol to data link
    addressing, such as Media Access
    Control (MAC), however all other
    aspects below that level are
    implicitly assumed to exist in the
    Link Layer, but are not explicitly
    defined.</p>
  </blockquote>