compressed domain knowledge is not exclusive specialist firewall anymore - everyone needs to know something about protecting the private network from public Internet, while maintaining Internet connectivity easy. Practical Firewall combines solid grounding in TCP IP firewall / strategy with advice on how to use different software firewall, which mostly freeware and shareware for Unix variants. He uses a sequence of events, for example, to contrast FTP with standard FTP under the proxy service. Conceptual material is supported by surveys firewall products, what they do, and what their relative merits Wall. - David Topics covered: Firewall concepts and practices, with emphasis on TCP Wrappers, TIS Firewall Toolkit, SOCKS, SQUID, ipfwadm, ipchains, and Microsoft Proxy Server 2.0.