If you set up the linux PC as the router/gateway/firewall and the outside cable connection is connecting to the PC then I assume there is a 2nd NIC that either conencts tot he Sw or the other PC? I got lost in the discussion
as trivia, RR in my areas issues a cable modem during their setup and inturn uses that mac address as a means of identfying the customer. Thus for any reason , which has happened several time do to NIC failures and computer HW changes, nothing network wise is compromised from their standpoint.......
I know this thread is a few days old, but I