Why Do I Need a Firewall?

Most people have been told that a firewall is essential by various others, from friends and family to the guy at the computer store. Everyone has different advice on what is needed and wanted, but all too often leave out why you need a firewall and what exactly a firewall does. As a result, many computer users are left with some confusion about firewalls and what a firewall does. Even many more advanced users may not fully understand the depth of protection that a firewall can offer.

Types of Firewalls

The basic function of a firewall is to block internet connections that are not wanted and may be malicious.

Many basic firewalls simply block any computer that tries to connect directly to your computer; called inbound connections. These firewalls allow your computer to connect out in any way they want and allow the requested data, but otherwise block any attempt to make an inbound connection unless you have configured it to allow specific types of connections. A list of rules is used to determine what types of connections are allowed and not allowed. These rules can apply to connections going both ways, but many firewalls simply allow any outbound traffic.

Most firewalls today will also check to make sure that the connections are carrying the correct type of information, and block connections that are deceptively trying to send something other than what they claim. This is called Stateful Packet Inspection, or SPI for short.

Software firewalls (aka personal firewalls) may also block unwanted outbound connections. These firewalls will wait for programs to try to connect out, halt the connection and show you a prompt. If you click to Allow then the connection will proceed, otherwise it will be blocked.

So why do I need one?

In the past most people didn’t really need a firewall because hackers didn’t have much interest in attacking the average person’s computer. For those that wanted some protection anyway, a basic firewall and antivirus program were all that anyone really needed. A basic firewall kept anything from coming in that the user wasn’t trying to get, and the antivirus would detect anything that was downloaded by email or over the web.

In today’s climate, a computer will usually be infected in a matter of seconds if connected to the internet without some type of firewall.

Unfortunately hackers are very smart, using tricks that basic firewalls don’t address and subvert antivirus programs. Attacks today are also often used for criminal purposes, such as collecting your personal information and sending it back to the hacker.

A new and sophisticated firewall, such as Online Armor, can block these kinds of tricks. So when malware sneaks by a traditional antivirus, the firewall can still block the connection back to the hacker even when they use tricks to get past other firewalls. Online Armor also watches what’s going on behind the firewall to help ensure that malware doesn’t even get the chance to use those tricks, providing multiple layers of protection.

I already have a router; do I still need a firewall?

Yes – a router is not a firewall. Routers split up an internet connection among multiple computers, so they can work as something like a basic firewall because they don’t know where to send any incoming connections that weren’t requested. Unfortunately they won’t restrict outgoing traffic in any meaningful way, and don’t block many of the tricks that an actual firewall can. The majority of internet users today have a router and/or a basic firewall, and hackers know how to work around these.

Even most so-called firewall routers can still be vulnerable to some older tricks that a personal firewall can protect against. New threats are emerging that even target routers without having to compromise your computer.

While a router does offer some basic and essential protection, it cannot provide the same level of protection as a personal firewall. Using both a router and a personal firewall together will provide the best protection.

If you have more than one computer plugged into the router then you will also want a personal firewall in the event that one of the other computers becomes infected and tries to infect yours.