An IP address is used to uniquely locate a NIC on a different subnet. A MAC is used to uniquely locate a NIC on the same Subnet.
So the IP address is used to hop across routers until it reaches the network the destination is a member of (192.168.0.0/24 for example). The router will then pass the packet to the MAC (NOT THE IP) address of the recipient. MACs are therefore necessary to allow communication on a network. I can't think of a disadvantage. Potentially it could have some privacy implications, because they obviously uniquely identify a PC, but this isn't really much of a concern, MACs aren't passed across routers. Once a packet leaves a given network, it uses an IP address until it reaches it's destination. Being able to change your MAC address is a mixed blessing. If you change your MAC to be the same as someone else's on your subnet, that can be really fun. Particularly if the troubleshooter isn't experienced. Old Card (Especially ARCnet (in my experience)) sometimes had duplicate MACs. Being able to change you MAC is part of the TCP/IP spec. Kev. ----- Original Message ----- From: "BentWig Nut" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, January 01, 2003 3:58 PM Subject: (clug-talk) MAC s > > Hello all. > > Q1: What are the pros and cons of a M.A.C. address? > > Q2: What are the advantages and disadvantages of being able to > > change the MAC ? > > Waiting for the roof to fall in... > > > > > > _________________________________________________________________ > MSN 8: advanced junk mail protection and 2 months FREE*. > http://join.msn.com/?page=features/junkmail > > >
