1. FIREWALL S.Sivarama Sarma Network Administrator

2. A firewall is a system that is set up to control traffic flow between two networks. Firewalls are most commonly specially configured Unix systems, but firewalls have also been built out of many other systems, including systems designed specifically for use as firewalls. The most common commercial firewall today is CheckPoint FireWall-1, but competitors such as Cisco's PIX are quickly catching up on CheckPoint.