How a Firewall Protects Your Computer and Network
A firewall is a cybersecurity solution that protects your computer and network from malicious attacks. It filters data packets entering and leaving your network and decides whether to allow the data through or not based on pre-defined security criteria. It also operates at various layers of the standardized Open Systems Interconnection model (OSI) to filter data packets in different ways, and it works with other software and hardware solutions for a complete network security system.
Firewall rules evaluate a variety of information about data packets, including the source address, destination address, port number, and protocol. They also include the action that should occur when a data packet meets or fails to meet the specified conditions. These rules are usually formulated by your network administrator, and they are applied to inbound and outbound data packets to determine whether the data is allowed or denied access.
In the physical world, a guard would assess where someone was trying to go, where they came from, and what they looked like before admitting them to a gated area. A firewall functions analogously, evaluating each data packet to decide if it should be allowed through and to what network location or if it should be turned around and sent back the way it came from.
For example, a sandboxed-enabled firewall prevents malware from installing on your device by sending the link you or your employees click to a virtual environment that can test the integrity of the program before it enters your computer. This feature is available in some free and paid firewall applications, such as Comodo’s patent-pending Clean PC Mode.