What is a “Firewall”?

In order to keep the internal network secure, we use a tool called “firewall”. So, what does a firewall do? A firewall is a tool that monitors incoming and outgoing network traffic from an internal network. Once a firewall detects any malicious incoming traffic, it blocks the traffic based on the rules that are pre-set to the firewall. A firewall keeps hackers and unwanted traffic from entering the internal network by blocking traffic that might be suspicious. There are three common types of firewalls that are packet filtering, application, and packet inspection. Let’s discuss each of them.

Packet Filtering: Packet filtering firewalls are the firewalls that examine the source and destination IP, also the port numbers to see if the traffic is safe to enter the network or not. If it is traffic that is harmful or unwanted, the firewall will block the traffic through the set of rules that are pre-established onto the firewall.

Application Firewall: Application firewall is a type of firewall that controls the incoming or outgoing traffic from an app. It decides whether the traffic should allow incoming or outgoing traffic from an app or to the app.

Packet Inspection: Packet inspection deeply inspects packets on the network to optimize network security. Every packet should be deeply analyzed to maintain high security for which a Packet Inspection firewall has been created.

You can see in the picture there is incoming traffic that is going through a firewall to an internal network. It will examine the incoming network traffic and if it detects something that shouldn’t be delivered to the machines within the internal network, then it will block that traffic.