What Is a Firewall?
A firewall acts as a barrier against unauthorised incoming and outgoing information. It does so by constantly filtering data packets based on programmed data characteristics such as the IP address of the information sources, key words and domain names. Firewalls are distinct from anti-viruses that work to prevent and remove malware, viruses and worms from computers and devices. Firewalls can come in the form of software or hardware and are often built into routers; a networking device that forwards data packets between computer networks. Broadband internet providers provide routers that have a firewall function to help secure their customers’ systems.
Packet-filtering firewalls, Stateful inspection firewalls, Circuit-level gateways and Next-gen firewalls all work to filter business based on predetermined security rules. Each has its own set of strengths and weaknesses.
Firewalls are a first line of defence against incoming threats that can compromise the integrity of internal IT systems and expose web businesses to unforeseen damage, loss or downtime. They monitor and control network traffic between an organisation’s private network or a web server and the outside world to identify unauthorized access, intrusion and attacks.
Host-based firewalls are a good starting point for any IT team attempting to reduce the risk of insider threats, but they can be limited in scope if their configuration relies on the device itself. To counter this, host-based firewalls can be combined with network firewalls to increase coverage. Many Microsoft operation systems (such as Windows XP, Seven, Eight and 10) have built-in host firewall capabilities.