Firewalls

Firewall??????

Firewall is anything hardware or software that can filter transmission of packets of digital information as they attempt to pass the boundary of the network

Roles of Firewall

• Packet filtering allow or deny packet transfer

• Application Proxy proxy for applications

Super Roles!!!• Logging • VPN services• Authentication• Shielding Hosts• Caching

Shielding Hosts

Authentication

Logging

Caching

VPN services

Terminologies• Protected Network• Un-protected network• Demilitarized zone• Dual Homed Firewall• Proxy• NAT• Stateful Packet Filtering• Policy • Rule Set• Allowed Traffic• Illegal Traffic• Rejected Traffic• Security Associations