identify client

[Matt Laoye]

Is there a way for the dhcp server to tell that the requests are from
the same client for machines with multiple interfaces?
We run dhcp registration, one of the problems is that laptop users need
to register twice: wired and wireless.
I wonder if there is any option or parameter that dhcp server can send to
the client when client register the first interface, and later,
when the second interface is used, we can tell that the two NICs belong
to the same host, thus user doesn't need to go through the  registration
process again.

So far the only option I can find is client-hostname, but it doesn't seem to
be a reliable information:
it can be easily changed  also not all clients send client-hostname.

Any suggestions and comments will be greatly appreciated.


Thanks,
Matt