View source for Firewall (computing)

==Prevalence==
Almost every modern computer is protected by some kind of firewall, at some point along the connection link.  Most network address translation (NAT) routers, include some form of firewall as well; even if not designed with a firewall, NAT routers can be barriers to some basic methods of attack due to the core functions of the device. The majority of networks in operation today do use NAT routers, meaning that most people are protected in this fashion.<br />
Additionally, many anti-virus programs now come with a software firewall.  However, even more common than this are firewalls native to the [[operating system]]. [[Windows Firewall]], for example, is a preinstalled firewall system in all modern versions of the operating system.<br />
This kind of popular protection is far better than nothing, but to ensure a network or device is secure, firewalls should not be as much of an add-on or an after-thought as a deliberate security measure.  When attacking a Windows device, the attacker knows for certain that they will need to circumvent the native firewall—therefore part of the standard attack planning includes a method to get around or through that firewall.  Some people say that windows firewall is a very good product,<ref>“ Windows 7 Firewall- Is it good enough? .” Microsoft Community, Microsoft, http://answers.microsoft.com/en-us/windows/forum/windows_7-networking/windows-7-firewall-is-it-good-enough/cc1c218a-0162-4b69-a9a9-194069d55ace. Accessed 8 Sept. 2017.</ref> while others argue that it is too trusting.<ref>“Is Windows Firewall Any Good??” Windows Legacy OS forum, CNET, https://www.cnet.com/forums/discussions/is-windows-firewall-any-good-204842. Accessed 8 Sept. 2017.</ref>  For this reason, third-party firewalls such as the ones which sometimes come with anti-virus software are favored. For those more concerned with securing their network, a separate hardware firewall may be desired as well.  Those who do not use such a device would be well advised to ensure that their NAT router's firewall firmware is up to date.