What is a Firewall?
Firewall is a cybersecurity tool that helps to filter network traffic based on specific rules and allows only healthy data packets to pass through. Firewalls are installed at the border of a private network and the internet to prevent any malware, spyware, or viruses from entering or leaving your business network. Firewalls are configured based on the security needs of your business and help to protect against threats by performing logging and auditing functions which in turn, provides valuable threat intelligence.
Depending on the configuration, firewalls have different methods to read and examine data packets at various network levels. For example, a proxy firewall reads all information going in and out of the device and checks it against the firewall rule sets to ensure no malicious information is being passed.
One of the most popular types of firewalls is stateful inspection. This firewall type creates a state table of established connections and then evaluates future data packets by matching them to this table. This means that if a new connection is made, the firewall can quickly decide whether it should be allowed or blocked based on its past experiences. This is considered a major improvement over packet filters that only look at the information on each individual packet and can be easily evaded by hackers who can use man-in-the-middle attacks to hijack existing connections.
A more advanced firewall is the Next-Generation Firewall (NGFW). This solution is the combination of traditional firewall capabilities, application awareness, and an intrusion prevention system (IPS). It uses a zero-trust policy and offers additional context to the firewall’s decision-making process which helps to identify sophisticated and unidentified cyberattacks.