What Is a Firewall?
Firewalls are a vital part of your network security system. They provide an additional layer of defense against cyber attacks and other threats by filtering data as it enters or leaves your network. This helps to prevent malicious content from entering your computer systems and sensitive information from leaking out of your organization.
A firewall is a piece of network hardware that acts as a barrier between an internal business network and the internet. It is inserted inline across a connection and inspects every packet that comes into or out of the protected network. It compares each packet to a set of preconfigured rules to determine if the data is safe to send or not. Firewalls can also monitor ongoing connections and automatically update their filtering rules based on past activity, which is known as stateful inspection.
Most modern firewalls include intrusion detection and prevention capabilities, which analyze network traffic to detect malicious behavior that would normally be missed by a simple traffic evaluation or packet filter. These built-in tools can also help to stop unauthorized users from gaining access to the organization’s network by detecting malware on their systems and stopping them from sending commands to other infected machines, which are often used to launch a cyberattack.
Firewalls can also prevent data leaks by analyzing the contents of a packet, such as its destination address and port number, to ensure that only the right kind of data is allowed into the network. This is useful for avoiding the risk of employees accidentally uploading sensitive information to websites such as Dropbox or using an always-on internet connection like Digital Subscriber Line or cable modems.