LARTC - Apr 2002 - mac address

Hello,

Would I be right in thinking that if I have a gateway running cbq like this:

Clients------------------eth0-Gateway-eth1-----------------------internet
10.0.0.0/8                  10.0.0.1            1.2.3.4

and I was doing..

#iptables -t mangle -A PREROUTING  -m mac --mac-source 00:00:00:00:00:01 -j
MARK --set-mark 1

 - where 00:00:00:00:00:01 was the mac address of one of my clients, I would
be unable to control traffic from eth0 to my client using the MARK, as
packets would have a source mac address of the internet server?

Or does the gateway remember the source mac address of the client when a
reply comes to it from the internet?

Thanks,

Gavin