People often use a hardware firewall without even knowing it. There are too many examples of hardware firewalls to name, but most of them share the same basic principle for protecting Internet users from malicious software. Although hardware firewalls are an effective security system by themselves, they work best in combination with other security methods.
When people talk about examples of hardware firewalls, they are actually referring to routers, which have natural firewall properties, reports CyberCoyote. A computer connected to a router has an address given to it by the router, while the router uses its own, single IP address to direct traffic. Thus, it is much more difficult to target any specific computer behind a router than one on direct connection.
All routers have hardware firewall-like attributes--Linksys is a very common producer of routers. However, more expensive types of routers, usually from the same companies as basic ones, are available that are designed to have specific features to prevent malicious users from mounting an attack, reports FirewallGuide. True hardware firewalls use a tactic known as "Stateful Pack Inspection" (SPI), such as the Linksys WRV200. SPI protection looks at the specific content of information traveling over the network for any harmful code. Basic routers only block certain computer ports and addresses.
Hardware firewalls are very effective at stopping viruses and worms from infecting a single computer. But routers have the disadvantage of spreading malicious software more easily to other computers on the network if any computer connected to them receives "malware"--such as a virus from a download--than if they were on separate connections, reports CyberCoyote.
Any wired or wireless router is a good example of a hardware firewall, but the vulnerability of other computers on the network usually causes network administrators to suggest a combination of a software firewall, anti-virus and a hardware firewall, reports FirewallGuide. A software and hardware combination can make up for each other's weaknesses and provide the best all-around protection.
No combination of hardware or software can ever completely protect a computer from viruses and malware. Hackers and nefarious users are always creating new types of programs to compromise a computer's security system. Users can put together a highly secure computer security system for under $200 as of 2009. This also requires downloading the most updated definitions and information from security vendors.