A firewall is your protection from the internet
Another place you might be familiar with a firewall is in your house. When a house with a garage is built, it needs a fire rated wall. The materials used to build the walls are fireproof.
These walls protect your house from fires starting in the garage.
Your wired and wireless network is your home on the internet.
Your house even has an address on the internet. You need protection for your house on the internet.
The firewall is what protects you from unwanted intruders.
How a firewall protects
In medieval times, entire cities were surrounded by a wall with 1 gate to get in.
A firewall is similar to the setup of medieval cities.
The firewall blocks all traffic coming in and out of a network. But a firewall has many gates. These gates are called ports.
Each port is assigned a number. The port numbers are standardized based on the protocol.
Here’s some examples of port numbers
- 80 — HTTP (Hypertext Transfer Protocol) basically the internet
- 53 — DNS (Domain Name System) for matching website address to IP addresses
- 443 — HTTPS (HTTP secure) same as 80 but encrypted.
Firewalls are setup to block traffic to all ports except for some commonly used ports. Like the examples above.
Software — A software firewall is installed on your computer. It helps keep intruders out of your computer. This type of firewall is an application installed on your computer. Windows and MacOS both have firewalls built in.
Hardware — Hardware firewalls are a server setup to filter your whole network’s traffic through. These can be a physical server or a virtual server.
Most people don’t have hardware firewalls installed at their house.
The closest thing you would have to a hardware firewall is your router. Newer router’s (some people might call them modems or their WiFi) have firmware (software installed in…