Firewalls – Packet Filters

Ø simplest, fastest firewall component

Ø foundation of any firewall system

Ø examine each IP packet (no context) and permit or deny according to rules

Ø hence restrict access to services (ports)

Ø possible default policies

l that not expressly permitted is prohibited

l that not expressly prohibited is permitted

11) What is Malicious Software? Describe DDOS and countermeasures.