OSI Levels and Firewalls

Just a little reference diagram I put together for my fellow CEH Hackers.

OSI Layer 7 – Application-Level firewall (Application level, HTTP, FTP)

OSI Layer 5 – Circuit-level gateway firewall (monitor TCP handshake,Session)

OSI Layer 3 & 4 – Packet filtering firewall (Network layer, Packet)

OSI Layer 3 & 4 – Stateful Firewall (Packet filtering, previous packet filtering, inbound traffic rules)

 

 

 

 

 

 

 

 

 

 

 

 

 

SYN, SYN-ACK, ACK