Learn more about what a firewall is in this article.
A firewall is a type of computer network security system that restricts internet traffic entering, leaving, and within a private network. It works by blocking and allowing data packets to prevent unauthorised web activities and web threats. In other words, they are borders that have policies that set the allowed and disallowed web activity in a private network.
Firewalls can be used for the following purposes:
Parental controls - Parents can block age-inappropriate web content from being accessed by their children.
Workplace and school browsing restrictions - Schools and workplaces often use firewalls to block undesirable or distracting content from being viewed.
Firewalls are considered the bare minimum and standard to network security. Networks with no firewalls are vulnerable to any traffic that is trying to access the system, including malicious traffic.
Firewalls work by deciding the traffic that is allowed to pass through and the malicious traffic. They then filter out the trusted from the untrusted based on previous network traffic patterns. In addition, firewalls can be a component of the operating system of a computer, since operating systems newer than Windows XP have a built-in firewall, called Windows Firewall, which will notify users in the event of any suspicious activity and block viruses, worms, and backdoors.
Types of Firewalls
Types of firewalls include:
Hardware firewall - These protect entire networks from the external environment with one device and are often installed between the computer network and the internet. They require advanced IT knowledge to install and are commonly used by large businesses when security is a huge concern.
Software firewall - These are installed on a user's computer and protect that one device. It offers customisability as users can block access to certain websites.
Packet filtering firewall - These are simpler and less expensive than other firewalls and work by performing basic data packet filtering, which analyses IP and port addresses in order to determine whether the packets can pass.
Proxy firewall - These act as an intermediary between the user and the network and only inspect internet traffic from a certain protocol and prevent direct connections from outside the network.
NAT firewalls - These allow a range of devices with different network addresses to connect to the internet using a single IP address, effectively hiding individual IP addresses. In the same way that proxy firewalls function as an intermediary between a group of computers and outside traffic, NAT firewalls perform the same functions.
Cloud firewalls - These are available on the internet instead of installed directly between two networks on hardware. These allow users to pass through the firewall and access the network using the internet. Some of these firewalls are intended for small private networks.
Stateful inspection firewall - Depending on the state of an attempted network connection, these allow or disallow packets. The state of the packet (or network connection) is identified by bits in the packet, and the firewall examines details about the attempted connection, such as the source address and size. Stateful inspection firewalls analyse packets in greater detail than other firewalls, which helps prevent malicious traffic. However, because the inspection takes longer, they may be slower.
UTM (Unified threat management) firewalls - Firewalls are only one feature of UTM and these are less secure. These types of firewalls combine firewall and prevention capabilities into a single platform.
Network segmentation firewalls - These restrict the areas of a private network that are accessible and can also be known as sub-firewalls for a sub-network (subnet). These can be expensive and difficult to set up.
NG (Next-generation) firewalls - These are currently used by businesses to provide enhanced network security. They provide additional security and monitoring features, such as deep packet inspection, UTM, IPS, and threat intelligence.
Origin
Originally, the word 'firewall' referred to a physical protective barrier from an actual fire in a city or between different buildings. The word 'firewall' was first used in 1983 with reference to networking and appeared in the film 'War Games'. It is believed that this networking term came from that film.
How To Allow A Program Through Windows Firewall?
Programs can be allowed and disallowed access through Windows Firewall. In order to perform this task, go to 'Control Panel' > 'System and Security', and 'Allow an app through Windows Firewall'. Then, a list of programs will be displayed, where the settings can be altered. Note that this will require administrator access.
