Some firewalls have superb configuration interfaces without having solid security features, while others focus on strong security functions without providing robust management tools. Fortunately for the consumer, the two are rapidly converging. There are currently several dozen products that offer firewall protection for your network. These products vary in price and offer a wide range of features. In addition, free public-domain firewall software is also available.
Users have to directly interact with the firewall.
Client software has to be replaced with proxy-aware clients. Proxies aren't available for a number of services. Unproxiable services are difficult to process. Performance is limited by the FWTK's design. There's no automated system administration assistance, thus requiring significant Unix knowledge by the administrator.