Firewalls cannot protect against attacks that do not go through the firewall. Firewalls cannot protect very well against things like viruses. There are too many ways of encoding binary files for transfer over networks, and too many different architecture and viruses to try to search for them all. Proxies are often used instead of router-based traffic controls, to prevent traffic from passing directly between networks. Many proxies contain extra logging or support for user authentication.
Proxy servers are application specific.
In order to support a new protocol via a proxy, a proxy must be developed for it. Related Sites pandoras-box.bgsm.wfu.edu Firewall fundamentals. Infoseek Enter words and phases that best express the subject of interest. Yahoo Yahoo organizes web sites into categories. You can either browse the categories or search them.