Different Types of Firewalls
Firewall is a computer network security system that limits internet traffic in to, out of, and within your private network. This hardware or software application is designed to help protect against cyberthreats and viruses by blocking or allowing data packets based on pre-established security rules.
Different types of firewalls analyze packets at different network levels, examining the information contained in each one to verify it’s safe. Some check only the address of a sender, while others inspect the data itself.
A firewall that works at the network layer analyzes incoming and outgoing internet communications using IP addresses — similar to postal codes that identify where a package will be delivered. It also checks the content of data packets, looking for anything that could be used to launch a cyberattack like malware or ransomware.
Packet filtering firewalls analyze data packets at the network, transport, and application layers to look for suspicious activity like viruses or malware that would cause a cyberattack. They can block specific website categories, detect malicious programs based on their behavior, and provide advanced scanning capabilities for files, including passwords.
A stateful multilayer inspection (SMLI) firewall analyzes the entire packet at the network, transport, and application layers, comparing each part to existing connections. This type of firewall can detect a wide range of threats and is often integrated with additional security software like antivirus, intrusion prevention, and cloud management to form unified threat management (UTM) systems. It can also detect denial-of-service attacks (DoS), which try to take advantage of established connections that this firewall assumes are safe.