What is a firewall? - Types of firewalls and how does a firewall work

Firewall introduction

Nowadays, the world is becoming digital. All companies want ranking in numbers. In this situation hacker attacks or hack companies data through threats or virus. All companies want to secure their sensitive data, which is useful to grow companies. But all sensitive data secure with basic tool or primary tool such as Firewall. All companies have their security system with strong firewalls.

What is a firewall?

A firewall is a network security system that monitors and controls incoming and outgoing network traffic which is based on security rules i.e. permit or block of data entry. A firewall establishes a barrier between trusted network and traffic from untrusted external network, i.e. internet.

A Firewall is also called types of cyber security. It is also prevent from viruses or hackers.

Here we will learn about…

• What is a firewall?
• Types of firewalls
• How does a firewall work?

 

Types of firewalls

Firewall can be divided into different categories based on their operations. Here we will know about important 5 types of firewalls.

1. Packet filtering firewalls
2. Circuit-level gateways
3. Stateful multilayer inspection (SMLI) firewalls
4. Proxy firewalls (Application Level Gateway)
5. Next-generation firewalls (NGFW)

1. Packet filtering firewalls    

          Packet filtering firewalls create a junction at traffic router or switch. The firewall performs like a checker of data packets which is coming from the router such as IP address, packet type, port number and other information without opening the packets of data to inspect its contents.

2. Circuit-level gateways

          As another relatively easy and quickly way to approve malicious content, circuit-level gateways verify the (TCP) transmission control protocol handshake and other network protocol meeting inception messages over the network as they are built up between the local and remote hosts to decide if the meeting being started is legitimate, regardless of whether the remote system is considered as trusted.

3. Stateful multilayer inspection (SMLI) firewalls

          Stateful multilayer inspection firewalls is the combination with packet inspection technology and TCP handshake. it is not only check each packet but also keep track of packet is the part of TCP or other network. Stateful multilayer inspection (SMLI) firewalls examine the whole packet and only allow passing if they pass each layer individually.

4. Proxy Firewall

          Proxy firewall acts as an application level. It means it is intermediary between two end systems. Proxy firewall filters your network and traffic source i.e. “application level gateway”. These firewalls are delivered through a cloud-based solution or another proxy device. The customer must send a request to the firewall, where it is then assessed against a lot of security rules and afterward allowed or blocked. It monitors traffic for layer 7 protocols i.e. HTTP and FTP. Proxy firewall provides considerable data security.

5. Next-generation firewalls (NGFW)

          Most recently released firewall product in market with latest features like "next-generation" architectures.The common features of next-generation firewalls include deep-packet inspection, TCP handshake and etc.

It has include other technologies such as IPS (Intrusion prevention system), Intrusion prevention system works automatically stop attack against network. 

Next-generation firewalls come in market with latest features and data more secure. Next-generation firewalls provide in depth security features to alleviate against threats and malware attacks

How does a firewall work?

Firewalls analyze incoming traffic, which is based on pre-installed program. Firewalls filter traffic coming from untrusted or unsecured sources to prevent attack. Firewalls work as a guard which is obstruction at an entry point of the computer and this is exchanged the information with external devices.

Firewalls monitor all types of information traffic which is entry in computer system to permit good information in but block bad information.

Conclusion

Now that you understand, firewalls introduction, what is a firewall, 5 different types of firewalls i.e. (1) Packet filtering (2) Circuit-level gateways (3) Stateful multilayer inspection (SMLI) firewalls (4) Proxy firewalls (5) Next-generation firewalls and how firewalls work.