I think you are talking more about NAT (Network Address Translation) than a firewall. However some firewalls (usually hardware i.e. cable/dsl rotuers) do this automatically. (thats how multiple people get on at the same time). Gonna need som more info to be a little more helpful. How do you connect to the internet? Why do you want to hide your real IP? Other than it being the first major step in securing your box. Just wanted to know if you needed to dod something specific. Hopefuly someone will be along soon who has more working knowlege of Noton than I do... but I'll see what I can find.
