Firewalls are the primary perimeter defense for most organizations that have gone through many iterations: proxy, stateful, Web app, next-generation

January 25th 2019, By Tim Greene and Brandon Butler



Firewalls been around for three decades, but they’ve evolved drastically to include features that used to be sold as separate appliances and to pull in externally gathered data to make smarter decisions about what network traffic to allow and what traffic to block.



Now just one indespensible element in an ecosystem of network defenses, the latest versions are known as enterprise firewalls or next-generation firewalls (NGFW) to indicate who should use them and that they are continually adding functionality.

What is a firewall?

A firewall is a network device that monitors packets going in and out of networks and blocks or allows them according to rules that have been set up to define what traffic is permissible and what traffic isn’t.



There are several types of firewalls that have developed over the years, becoming progressively more complex and taking more parameters into consideration when determining whether traffic should be allowed to pass. Firewalls started off as packet filters, but the newest do much much more.



Initially placed at the boundaries between trusted and untrusted networks, firewalls are now also deployed to protect internal segments of networks, such as data centers, from other segments of organizations’ networks.



They are commonly deployed as appliances built by individual vendors, but they can also be bought as virtual appliances – software that customers install on their own hardware.



Here are the major types of firewalls.



Full Article.