you do _not_ want to assign ethernet addresses
what you want is to assign IP addresses
the standard configuration in your case is to set the machine which has the
internet connection as a gateway for the home lan. it will get one (and
only one) public ip address from the provider through the wan
I'm planning to set up a home Ethernet of three computers. I'd like to set
it up so all three users can surf the net and receive individual emails. I
plan to have two machines using red hat 7.2, (one will have an internet
connection and be the web, print and mail server for the network) and
ano