Residential broadband "NAT" routers which allow many computers to share a single Internet connection are becoming quite popular. We love them for the security they provide to the machines placed behind them since any NAT router functions as a natural and excellent hardware firewall.

However, the Internet or "WAN" (Wide Area Network) side connection of many NAT routers and DSL gateways is not as secure as it should be. Many routers ship with web, ftp, or Telnet management ports wide open! And many are still configured with their well-known default administrative passwords. Although the router may be protecting the machines behind it, it might not be protecting itself without your deliberate closing of remote "WAN" administration ports.

Software firewalls like ZoneAlarm are an added security and safe guard against these and other security threats.