A controversial tool that has had its effectiveness doubted these last years, the “Firewall” is a software or hardware-based security system that controls the incoming and outgoing traffic in a network. Firewalls analyze the data packets and determine whether that information should be allowed through or not, based on a few defined rules and establishes a barrier between trusted and untrusted networks.

A firewall’s job is similar to a physical door that keeps a fire from spreading from one area to the next in a building. Those doors are called firewall, and just like that, computer firewalls are designed to prevent unauthorized access to or from a private network.
Unified Threat Management appliances or UTMs are often confused with firewalls, but in reality UTMs are part of firewalls, which can be software based or hardware based. The notion of UTM came out of the idea of multipurpose appliances back in the day. Today’s UTM is a sophisticated, multipurpose tool that can sit as a gateway and provide everything.

According to Gartner, the famous IT research company, a UTM’s definition provides at least the following functionality:
• standard network firewall.
• remote access and site-to-site virtual private network (VPN) support.
• web security gateway functionality (anti-malware, URL, and content filtering)
• network intrusion prevention focused on blocking attacks against unpatched Windows PCs and servers

A lot has been said about Next-Generation Firewalls (NGFWs) lately. This category of the product attempts to address the traffic inspection and application awareness problems of firewalls, without hampering performance. Having said that, the most significant difference between Next-Generation Firewalls and traditional firewalls is that NGFWs are application-aware; they use a variety of techniques to identify applications, including Web applications.

How do Firewalls and Next Generation Firewalls work?
Firewall rules uses some of the following policies to define whether to block or allow traffic: source and destination IP, source and destination port, and protocol. But according to Gartner, Next-generation firewalls (NGFWs) are deep-packet inspection firewalls that move beyond port/protocol inspection and blocking to add application-level inspection, intrusion prevention, and bringing intelligence from outside the firewall

McAfee recently published an infographic illustrating the 25 years of the Firewall and it’s developments.

Gartner Magic Quadrant for Enterprise Network Firewall 2016
The enterprise network firewall market is composed of appliances for securing enterprise corporate networks. These firewalls must be able to support single-enterprise firewall deployments and large and/or complex deployments, including branch offices, multi-tiered demilitarized zones (DMZs) and, increasingly, the option to include virtual versions. These products are accompanied by highly scalable management and reporting consoles, and there is a range of offerings to support the network edge, the data center, branch offices, and deployments within virtualized servers

Gartner Magic Quadrant 2016 Firewall

Gartner Magic Quadrant for Unified Threat Management – UTM – 2016

Gartner has released on August 30th, the 2016 Magic Quadrant for Unified threat management.

Gartner Magic Quadrant for UTM 2016

This video from Cisco, helps you understand quite well how firewalls work.

And this amazing video shows how China uses a firewall to allow information in and out of the countries internet and monitor what people in that country post online.