Same MAC address on 3550

Do you have the 3550 acting as a switch or a router for the purpose of the clients reaching the 760wl? If it is configured as a router to reach the 760wl then it -must- use its own MAC; the 760wl would not be able to reply if it received original MACs in that case.

It is being used as a router. I have 8 separate networks plugged into the the 3550 with port 48 going to the 760, which then of course is connected to the firewall. What you are telling me is it doesn't matter what the mac address is on any of the clients, the 3550 will strip it from the outbound packet and place the mac address of port 48 in the packet before forwarding it to the 760. From the 760 point of view, the packets it gets may have different source ip addresses, but the source mac address will always be the same. Am I correct?

Yes, that is correct. That is the way routing works.

If you for some reason -need- the original MACs on the 760wl, then the 760wl will have to be on the same segment as those other hosts, and some way would have to be found to allow the 760wl to talk directly to the hosts. -Potentially- you could do that by giving all those hosts a static ARP for the IP address of the 760wl. If all of the clients are Windows 2000 or later windows, then if the 760wl were defined as their default gateway, they could talk (through a MS hack) talk directly to the 760wl even though it was on a different subnet. If the 760wl needed to initiate conversations with the clients, you'd run into problems, though.

Getting original MACs through both ways across multiple subnets is not always impossible, but it isn't the way networks are designed, and solutions tend to be fragile. Could make a mess of internal communications, for example.