Lotus Foundation Server comes with a self-configuring Firewall that keeps unwanted visitors out of your network. This is A Good Thing.
If you do want to let some of The Great Unwashed past the Firewall (perhaps to look at a few public web pages or to place an order) then you can do that with the integrated LFS 'Fast Forward' module. FastForward allows you to create up to four sites on your server with each site mapped to a separate IP address. Those IP addresses can then be mapped to your Domain Names so you could run four separate web sites.
Let's imagine that you own the IP block from 220.127.116.11 to 18.104.22.168 and are looking to use them to permit Public access to four different web pages (each with its own layout and color scheme) on your server.
Travellers.org maps to 22.214.171.124
BudgetFlights.com maps to 126.96.36.199
LowCostHolidays.net maps to 188.8.131.52
SuperSaverAirFares.com maps to 184.108.40.206
This can be really handy if your customer wants to get three quotes before he makes a decision :)