In the beginning was the firewall, and it was pretty good. A big box of rules that sat between your network and the evils of the Internet, the firewall examined ports and protocols to decide which packets got in and which were barred at the door. Then things got, as things often do, complicated. New threats came sneaking in on trusted protocols, ports and protocols became tangled, and looking inside packets became just as important as noting their source, destination, and type.
Protecting a network now meant deploying multiple firewall types (network, endpoint, application), anti-virus protection, content filters, intrusion detection systems, and more. Instead of a big box of rules, you needed a relay rack stuffed top to bottom with appliances -- each with its own administrative interface, and each representing a possible point of failure in the network. There had to be a better way, especially for smaller companies that couldn't afford a massive staff to feed and care for the relay racks full of appliances -- and thus, the unified threat manager (UTM) was born.

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