PFSense Firewall

Firewall Generations

1^st Generation Firewall - Packet Filter Firewall

Works up to the 3^rd layer of OSI models.

Based on IP addresses.

2^nd Generation Firewall - Stateful Filters

Works up to the 4^th layer of OSI models.

Based on IP addresses & Port numbers.

3^rd Generation Firewall - Application Firewall

Works up to the 4^th layer of OSI models.

Based on IP addresses, port numbers & application protocols.

4^th Generation Firewall - UTM (Unified Threat Management)