Good question!
Web surfing was handled by a proxy server that was running inside Smoothwall. It had it's own port and the browser settings(Firefox-Preferences) were pointed to use that 'IP

ort#' except for addresses on the LAN. I used another browser(Galeon, with it's home page set to: https://smoothwall's local(Green NIC) IP) to access the administration fuctions on the 'smoothwall' machine - logs, settings and the like.
When Firefox requested a web page, the request went to the Squid proxy server and the proxy took care of it, DNS , of course, and all, then sent the reply back.
By default, Smoothwall offered three ports (after the proxy server was enabled through the admin center). 800, 81 and 441. Firefox was successful going out port 800. Galeon got to the admin center through either 441 (https and prefered) or 81(http), I think it was 441 folowed by a login.
Whatever I tried, I couldn't get the same situation set up for RPM or YUM..