What Is a Firewall?
Firewalls, sometimes called network firewalls or a router’s firewall, are the devices that monitor and control network traffic. They’re a vital part of any enterprise security strategy, preventing bad actors from gaining access to sensitive data and damaging networked assets.
Firewall Rules Explained
A firewall can block, allow or drop network traffic based on pre-established rules. These can be as simple as “accept all traffic from my web server,” or as complex as “reject all outgoing connections to all untrusted sources.”
Packet-filtering Firewalls
In this type of firewall, the router performs a surface-level check of incoming packets. It inspects surface-level information, such as the destination and origin IP address, port number and packet type. Then it compares this information with its state table, which lists all established connections that the firewall considers safe.
Proxy Firewalls
In contrast to packet-filtering firewalls, proxy firewalls provide additional checkpoints between external networks and internal computers. They also offer more in-depth inspection capabilities, using application-level data to identify and filter out unwanted data.
Integrated ML/AI and NGFWs
In addition to traditional rules, modern firewalls use machine learning (ML) and artificial intelligence (AI) to analyze incoming and outgoing network traffic. Those technologies can help a firewall make smarter decisions and detect new cyber threats, malware, zero-day attacks, brute force attacks, unauthorized access and more.
Despite taking the best precautions, hackers are always finding new ways to break into and compromise an organization’s network. It’s essential to have the right firewall for your business and to update it regularly.