Network Firewalls are the devices that are used to prevent private networks from unauthorized access. A Firewall is a security solution for the computers or devices that are connected to a network, they can be either in form of hardware as well as in form of software. It monitors and controls the incoming and outgoing traffic (the amount of data moving across a computer network at any given time ).
An inner network is protected by a network firewall by keeping it separate from the outside network. A network developed inside of an organization is referred to as an inner network, and a network outside of an organization is referred to as an outer network.
Types of Network Firewall :
- Packet Filters –
It is a technique used to control network access by monitoring outgoing and incoming packets and allowing them to pass or halt based on the source and destination Internet Protocol (IP) addresses, protocols, and ports. This firewall is also known as a static firewall.
- Stateful Inspection Firewalls –
Additionally, it is a sort of packet filtering that regulates how data packets pass through a firewall. The term “dynamic packet filtering” is sometimes used. These firewalls can check to see if a packet is a part of a specific session or not. It only allows communication if and only if the session between the two endpoints is completely established; otherwise, it will prevent communication.
- Application Layer Firewalls –
These firewalls can examine application layer (of OSI model) information like an HTTP request. If finds some suspicious application that can be responsible for harming our network or that is not safe for our network then it gets blocked right away.
- Next-generation Firewalls –
These firewalls are called intelligent firewalls. These firewalls can perform all the tasks that are performed by the other types of firewalls that we learned previously but on top of that, it includes additional features like application awareness and control, integrated intrusion prevention, and cloud-delivered threat intelligence.
- Circuit-level gateways –
A circuit-level gateway is a firewall that provides User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) connection security and works between an Open Systems Interconnection (OSI) network model’s transport and application layers such as the session layer.
- Software Firewall –
The software firewall is a type of computer software that runs on our computers. It protects our system from any external attacks such as unauthorized access, malicious attacks, etc. by notifying us about the danger that can occur if we open a particular mail or if we try to open a website that is not secure.
- Hardware Firewall –
A hardware firewall is a physical appliance that is deployed to enforce a network boundary. All network links crossing this boundary pass-through this firewall, which enables it to perform an inspection of both inbound and outbound network traffic and enforce access controls and other security policies.
- Cloud Firewall –
These are software-based, cloud-deployed network devices. This cloud-based firewall protects a private network from any unwanted access. Unlike traditional firewalls, a cloud firewall filters data at the cloud level.
Which firewall is best for your enterprise?
Choosing the right type of firewall means answering questions about what the firewall is protecting, which resources the organization can afford and how the infrastructure is architected. The best firewall for one organization may not be a good fit for another.
Issues to consider include the following:
- What are the technical objectives for the firewall? Can a simpler product work better than a firewall with more features and capabilities that may not be necessary?
- How does the firewall itself fit into the organization’s architecture? Consider whether the firewall is intended to protect a low-visibility service exposed on the internet or a web application.
- What kinds of traffic inspection are necessary? Some applications may require monitoring all packet contents, while others can simply sort packets based on source/destination addresses and ports.
Many firewall implementations incorporate features of different types of firewalls, so choosing a type of firewall is rarely a matter of finding one that fits neatly into any particular category. For example, an NGFW may incorporate new features, along with some of those from packet filtering firewalls, application-level gateways or stateful inspection firewalls.
Understanding the architecture and operations of the private network to be secured is the first step in selecting the best firewall, but it also necessitates knowledge of the various firewall types and firewall policies that work best for the enterprise.
Whichever type(s) of firewalls you choose, keep in mind that a misconfigured firewall can, in some ways, be worse than no firewall at all because it lends the dangerous false impression of security, while providing little to no protection.