What does a firewall do?
Options
- It filters network traffic using allow or block rules (Correct option)
- It encrypts the whole hard disk of the computer
- It makes the internet connection run much faster
- It stores the passwords of all the users safely
Answer
Filters network traffic with rules, allowing or blocking connections
Why
A firewall sits between networks (for example the internet and your servers) and decides which connections are allowed, based on rules about address, port and protocol.
Example rule: allow port 443 (HTTPS) from anywhere, block everything else.
In AWS, a security group is described as a virtual firewall for your instances.
Remember
Firewall = rules about which connections are allowed.