Lets say that I have DSL service and Norton Antivirus 2003 on my system. Do I need firewall protection ?
Virus protection is one thing. Its essential. But equally essential is a competent firewall product because your DSL connection is always on. A firewall is the only way to statefully inspect all packet exchange between your machine and the internet. It should stop known harmful activity, warn about suspect packets and thwart any malicious activity from inside your machine attempting to use your DSL access.