Summary
Linksys broadband routers provide a simple, NAT-based packet-filtering router solution (some of which include stateful packet inspection) for small office environments as well as for home-based networks and users. Although some broadband router models lack the robustness of stateful packet-inspecting firewalls and lack granularity for configuring port forwarding, you can use them in simple environments where the security risk does not justify a substantial investment. If you require granular filtering rules, or if you require more advanced filtering mechanisms than simple NAT and port forwarding, you should consider implementing a more advanced firewall such as the Cisco Secure PIX Firewall, Microsoft ISA Server, or NetFilter over Linux.