MAC Address

Michael Renzmann mrenzmann at dylanic.de
Fri Oct 18 16:38:12 EST 2002


Hi.

Martijn van Oosterhout wrote:
> I guess it's because when sending a packet, the card doesn't even look at
> it's own MAC address. 

That is right, for SENDING. But as in wireless networks every receiption 
of a packet from the correct destination gets acknowldeged, the card 
looks at its own MAC address whenever a packet is received. It the 
destination MAC corresponds with the one it is locally using, the packet 
is destined for it and an ACK gets sent to the sender. Else the packet 
is just thrown away.

> There are many reasons why the packets you send would not have your MAC
> address, bridging being the obvious. 

Yeah, correct, too. But the above mentioned characteristics of a wlan is 
the reason why you can't use bridging as long as the card supports the 
normal client-mode-communication-packet-header (which is capable only of 
telling something about the sender and the receiver of this packet, but 
not who originally created the packet) - the destinated card which 
receives the packet would acknowlegde it to another MAC than the one who 
sent the packet in the wireless media.

Bye, Mike




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