A software firewall works by filtering out unwanted inbound and outbound traffic, which makes your computer or other device more secure from external threats, viruses, and malware. To understand how this type of firewall system works, you must first know how different networking protocols work in conjunction with each other to accomplish file sharing and communication on the Internet. It’s not as complex as it sounds! In this article, we’ll discuss how software firewalls work so you can learn more about the security measures in place around the globe that help prevent cyberattacks from the outside world. Read about How Does a Software Firewall System Work?
Domain Name System (DNS)
A software firewall system works by intercepting all incoming and outgoing traffic on a network and filtering it based on a set of predefined rules. DNS is one of the key components of a software firewall system, as it is responsible for translating human-readable domain names into IP addresses. DNS allows the firewall to block or allow traffic based on the domain name, rather than the IP address. This makes it much more difficult for attackers to bypass the firewall. When an attack comes in from an unfamiliar IP address, the software firewall will not know what type of content might be coming from that IP address and can only filter based on its previous knowledge of which domains are safe.
Network Address Translation (NAT)
NAT is the process of translating between two different IP address formats. This is necessary because many internet applications and protocols expect IP addresses to be in a specific format.
A software firewall system uses NAT to control traffic between networks. By using NAT, the firewall can change the source and destination of packets. So that they appear to come from the same network. This allows the firewall to control which packets are allowed through and which are blocked.
A software firewall system uses packet filtering to control the traffic that is allowed to enter and exit a network. Packet filtering inspects each packet that passes through the firewall and compares it to a set of rules. If the packet matches a rule, it is allowed to pass; if it does not match, it is blocked. Incoming packets are checked against a list of known good hosts or IP addresses, which may be predetermined by an administrator or automatically assigned to particular users. Outgoing packets are compared against a list of bad addresses such as IP addresses belonging to spammers or hackers.
Stateful inspection firewalls
A stateful inspection firewall is a type of firewall that tracks the state of each individual connection traversing the firewall and makes sure that only legitimate traffic is allowed. This type of firewall typically uses a set of rules to determine what traffic is allowed and what isn’t. The best way to think about this type of firewall is as a person who checks your ID card at the entrance, then compares it with his own ID card. Once he has verified your identity, he lets you in. If someone were to come up behind you and try to go through the door without an ID card, he would stop them from entering because they are not on his list.
Application layer firewalls (Layer 7)
Application layer firewalls, also known as Layer 7 firewalls, are one of the most common types of firewall systems. They work by inspecting the content of incoming and outgoing packets and comparing them against a set of rules. If a packet doesn’t match any of the rules, it is blocked. The data in the packet can be analyzed. It should be allowed through or not, so there’s no need for excessive traffic inspection.
A key feature of an application-layer firewall is that it can block harmful behavior such as SQL injection attacks (SQLi) and cross-site scripting (XSS).
Application-layer firewalls typically use complex rules that allow many features to be configured with precision. This is important when you ask How Does a Software Firewall System Work?
Deep packet inspection
A software firewall system uses deep packet inspection to control traffic in and out of a network. It examines each packet of data that comes through the network and checks it against a set of rules. If the packet doesn’t match any of the rules, it is blocked. If it does match one or more of the rules, then the appropriate action can be taken. The action could be as simple as allowing access. As complex as sending an email alerting someone that a piece of malware has been detected.