What is a Firewall and How Does it Work?
Firewall is a computer network security system that monitors access to your PC and prevents malicious activity. A firewall works by blocking or allowing data packets and by analyzing the details of each packet to detect suspicious activity. It also prevents malware from spreading to other computers in a private network.
Firewalls are the best way to fend off viruses and other malware that can infect your PC, which can be extremely damaging. However, many people don’t know much about firewalls and how they work. In fact, many don’t even have one activated on their PCs. In this article we will look at what a firewall is, how it works and why you need one.
A firewall is a piece of hardware or software that monitors all incoming and outgoing data from your computer. It does this by checking a list of established rules and analyzing the information in the data packets to determine if it is malicious or not. Firewalls work by examining the Protocol, IP address and port numbers of the data packet before letting it through. This is why a basic PC firewall blocks everything (except the web browser) and only allows specific applications to be run if the user explicitly clicks “yes” in Windows UAC when installing new programs.
A firewall can also act as a filter to control how your computer can communicate with other devices on a network such as a printer or a scanner. It does this by examining the destination of the data packet and comparing it to the current state table of open connections. If the data is new, the firewall will analyze it using a rule set, and if it is already an ongoing connection then it’s just passed on to be processed by an application.