Firewall in Computer Network
A firewall is a type of network security system that uses preset security rules to monitor and manage all incoming and outgoing traffic. A firewall helps stop unwanted access while permitting legitimate communication to flow through by serving as a barrier between a trusted internal network and untrusted external networks, like the internet.
Software-based, hardware-based, or a combination of the two, firewalls are frequently found in security systems at the individual and corporate levels. They have the ability to filter traffic according to protocols, ports, IP addresses, domain names, or particular content patterns. Firewalls are essential for safeguarding private information and preserving a network's overall integrity because they enforce stringent access rules.
Types of Firewall in Computer Network
- Packet Firewall
- Stateful Inspection Firewall
- Application Firewall
- Next-Generation Firewall
- Circuit-Level Gateway
- Software Firewall
- Hardware Firewall
- Cloud Firewal
1. Packet Firewall
In order to decide whether to let or prohibit network traffic, a packet filtering firewall examines each individual data packet in accordance with pre-established rules. Usually, source and destination IP addresses, port numbers, and protocols serve as the foundation for these rules. Essentially, it works as a gatekeeper, evaluating each packet and deciding whether it satisfies the security criteria to pass through or is refused.
2. Stateful Inspection Firewall
In order to make well-informed decisions about whether to accept or block packets, a stateful inspection firewall tracks the status of active connections while monitoring and analyzing network traffic. By preserving connection context, such as source and destination IP addresses, port numbers, and sequence numbers, it goes beyond basic packet filtering. This gives it the ability to distinguish between unexpected or malicious traffic and legitimate traffic, resulting in a higher level of security.
3. Application Firewall
An application firewall, sometimes referred to as an application layer firewall, is a type of security system that keeps an eye on and regulates traffic going to and coming from services and applications. Application firewalls analyze traffic at the application layer (Layer 7 of the OSI model), as opposed to the network layer, as standard firewalls do. This enables them to comprehend the communication context and make better decisions about what traffic to allow or deny.
4. Next Generation Firewall
A network security tool known as a next-generation firewall (NGFW) offers sophisticated features like application awareness, intrusion prevention, and cloud-delivered threat intelligence that surpass the capabilities of a typical firewall. In essence, it improves defense against contemporary, complex cyberthreats by fusing the capabilities of a conventional firewall with extra security measures.
5. Circuit Level Gateway
One kind of firewall that functions at the OSI model's session layer is called a circuit-level gateway. By serving as a relay to forward packets without closely examining each packet's contents, it confirms the validity of TCP or UDP sessions between internal and external hosts.
6. Software Firewall
Installed on a computer or server, a software firewall is a program that monitors and regulates network traffic according to predetermined rules, serving as a security barrier. By filtering both incoming and outgoing data packets, it protects the device from undesired or harmful connections by letting only permitted traffic through.
7. Hardware Firewall
A physical device used to impose a network border is called a hardware firewall. This firewall can inspect inbound and outbound network traffic and impose access rules and other security policies because all network links that cross this border go through it. These firewalls can provide a range of networking and security functions, such as URL filtering, an intrusion prevention system (IPS), and even Wi-Fi capability. They have the hardware and software components required to enforce a network boundary.
8. Cloud Firewall
Similar to how a traditional firewall protects on-premises networks, a cloud firewall, also called Firewall-as-a-Service, is a security service that filters network traffic to protect cloud resources. It functions in the cloud and creates a virtual barrier around cloud platforms, infrastructure, and apps. Because cloud firewalls are scalable, available, and manageable centrally, they are an essential part of cloud security.
