Role of Firewall in A Network Infrastructure

We have all heard of the term firewall, even though we may not know what role it plays in network infrastructure. We may have a basic understanding that it provides a gate keeping service and we may know it is important, but our IT security management knowledge might be limited to this vague understanding.

Knowing about the role of firewall in network infrastructure is beneficial, especially if you are hiring IT experts like ITaffix Technologies for IT security management services.

What is Firewall?

Before looking at the role of firewall, it is important that we look at firewall and what it is. Firewall can be described as a software or firmware that enforces a set of rules about what data packets are allowed to enter or leave a network. Firewalls are used to filter traffic, lowering the risk of malicious packets in the public internet affecting the security of a private network.

There are two main types of firewall; host-based and network-based. Host-based firewall is installed on the incoming and outgoing signals of individual servers and monitors. When the firewall is built into the cloud infrastructure or installed as a virtual firewall service, it is network-based.

However, other types of firewall can also be found depending on the place and activities they control. These include packet-filtering firewalls, stateful inspection firewalls, proxy firewalls, and next-generation firewalls.

In order to understand the role of firewall in a network infrastructure and why IT experts like ITaffix Technologies offer 24/7 IT services, we need to look at the different types of firewall separately.

Packet-Filtering Firewall

One of the types of firewall used in network monitoring, packet-filtering firewall checks the source, destination address, protocol and destination port number when a packet passes through it. If the packet doesn’t comply with the rule set of the firewall, it isn’t forwarded to its destination.

While packet-filtering firewall is effective, they can be vulnerable to IP spoofing attacks because they process each packet in isolation. This type of firewall has been mostly replaced by stateful inspection firewalls.

Stateful Inspection Firewall

This type of firewall is also known as dynamic packet-filtering firewall. It maintains a table that keeps track of all open connections, so that when a new packet arrives, the firewall compares information in the packet header to the state table. It then determines whether it is part of an established connection.

The packet is allowed through if it is part of an existing connection; however, it is evaluated further if it doesn’t match an existing connection. While a stateful inspection firewall is effective, it is also vulnerable to denial-of-service or DoS attacks.

Proxy Firewall

Since packet filtering and stateful inspection firewalls fail to differentiate valid application layer protocol requests, data and malicious traffic were enclosed within apparently valid protocol traffic. This led to the need for better IT security management and firewalls to protect networks from attacks in the application layer.

This in turn led to the creation of firewalls that provided application layer filtering, which looked at the payload of a packet. This gave IT experts like ITaffix Technologies more control over network traffic, and putting this firewall on a proxy server meant that an attacker couldn’t easily find the location of the network, thus creating another layer of security.

Next-Generation Firewall

Changes in trends and infrastructure have led to the need for 24/7 IT services and IT security management. The way in which traffic moves has also made IT experts go from the traditional three-layer data centre infrastructure to various leaf-spine architectures.

This has led to the realisation that while firewalls are still important, there was a need for stronger access control and security. This takes us to next-generation firewalls or NGFWs, which combine the capabilities of traditional firewalls with quality of service functionality and features that are not traditionally found in these products.
Looking at these types of firewall, it is clear what the role played by firewall in IT security management is. The importance of firewall cannot be stressed enough, which is why businesses choose to hire IT experts like ITaffix Technologies for 24/7 IT services and network monitoring.