Firewall(N/A)
A security system that inspects and controls network traffic based on predefined rules.
What is Firewall?
In one sentence: Firewall is like a border guard — decides who can enter the network and who can't!
Imagine you have a country. You have borders, customs, guards. Not everyone can enter. Must be checked, have permit. Firewall is this for your network — inspects traffic, if allowed lets through, if not, blocks.
Types of Firewall:
Packet Filtering: Checks packets (IP, port). Simple.
Stateful Inspection: Also checks connection status. Smarter.
Proxy Firewall: Acts like intermediary. Traffic goes through it.
Next-Gen Firewall: Deep packet inspection, intrusion detection, has antivirus.
How does Firewall work?
You have some Rules:
- Allow port 80 (HTTP)
- Allow port 443 (HTTPS)
- Block port 22 (SSH) from outside
- Block all traffic from IP X
Every packet that comes or goes, gets checked against these rules.
Why is it important for security?
Because firewall is the first line of defense! Blocks many network attacks, closes unnecessary ports, blocks suspicious traffic.