Fire Wall Layer/ 3/4/5 And Layer 7

Question 1

Layer 3/4 Firewalls
How do they work?

Answer 1

No memory of the request and response being related.
Treats each packet separately.
Used for basic security.

Memory Hook: “Layer 3/4 = No memory, no link.”

Question 2

Layer 5 Firewalls
How do they work?

Answer 2

Remembers the session (request and response linked).
Provides contextual security.
Used for advanced security.

Memory Hook: “Layer 5 = Remembers the session.”

Question 3

Difference between Layer 3/4 and Layer 5 Firewalls?

Answer 3

Layer 3/4: No memory, checks packets one-by-one.
Layer 5: Tracks the session, remembers the whole conversation.

Question 4

What does a Layer 7 Firewall do?

Answer 4

Inspects data at the Application Layer (Layer 7).
Understands specific protocols (like HTTP).
Looks inside the actual content of the traffic.

Memory Hook: “Layer 7 = Smart Firewall”

Question 5

What can a Layer 7 Firewall identify?

Answer 5

Normal requests (safe).
Abnormal requests (like malware, spam, or exploits).

Memory Hook: “Layer 7 = Blocks bad stuff”

Question 6

How does a Layer 7 Firewall handle encrypted traffic?

Answer 6

Decrypts (like HTTPS) to check data.
Re-encrypts after checking.

Memory Hook: “Layer 7 = Decrypts to inspect, then encrypts again”

Question 7

What actions can a Layer 7 Firewall take?

Answer 7

Blocks bad data (malware, spam, etc.).
Can tag or replace bad content.

Memory Hook: “Layer 7 = Blocks, tags, or replaces”