The Importance of a Firewall
Firewall is a network security system that guards your internal network from hackers and malware by filtering and allowing incoming data packets to enter or leave the computer system depending on a set of preconfigured rules. It is a crucial part of any business in today’s highly connected world. Keeping cyber attacks at bay, firewalls prevent theft of critical information and maintain privacy.
A firewall is a hardware or software device that monitors all incoming and outgoing network traffic. It inspects all the incoming and outgoing packets of data by examining their contents and source and destination addresses. Then, based on the set of rules it applies an action (accept, reject or drop) to that particular data packet.
For example, if your employees are attempting to upload credit card information from their work computers to Dropbox, the firewall will detect it and block the data transmission to prevent the possible theft of critical customer information. The same can be done for other malicious activities like sending spam emails.
The firewalls also protect the integrity of the internal network by preventing unauthorized changes to the firewall configurations. For this, the firewalls enforce a service access policy that limits internet-specific usage and requires user permission before an authorized administrator can alter the firewall configurations.
There are many different types of firewalls. For example, the oldest type is called a packet-filtering firewall. These firewalls filter network traffic by looking at the header of each data packet. Similarly, a circuit-level gateway firewall monitors network traffic at the session layer of the OSI model by inspecting TCP handshaking between two hosts.