Firewalls: taxonomy 1. Traditional packet filters a filters often combined with Major firewall vendors router, creating a firewall Checkpoint ciscoⅨ 2 Stateful filters 3. Application gatewaysFirewalls: taxonomy 1. Traditional packet filters ❑ filters often combined with router, creating a firewall 2. Stateful filters 3. Application gateways 6 Major firewall vendors: Checkpoint Cisco PIX