Network security - OSI model & 5 types Firewall

OSI model

1. What is OSI?

2. Explain what each layer does in detail.

3. Give examples.

1page for each layer

Firewalls

No need to give definition of firewall, you only need to focus on explaining each type in detail.

for example: What it does, advantages and disadvantages. And the reason of causing the advantage or disadvantage.

1. Packet Filtering Firewall

2. Stateful inspection firewalls

3. Application Proxy gateways

4. Circuit-level gateways

5. Personal Firewall

1page for each type