Technology

Learn About Firewalls, How They Operate, and Why You Need Them

As you may know, a firewall is a barrier that prevents intruders from crossing into your private network or gaining access to your computer via the Internet. It functions similarly to a home security system. Many people in Hawaii, including me, never bother to lock their doors, and we never have any issues.

When your computer is connected to the internet (which it is if you have high-speed internet like DSL or cable, 24/7), it’s as if the entire world is next door to your “house,” so, unfortunately, you have to act as if your neighbors are all criminals because anyone, anywhere in the world, can break into your computer.

Imagine a house with many windows, some open, some closed; this is how your network or internet connection works; many ports have specific purposes, such as port 25, which is typically used for sending email.

A firewall works by closing off unused network connections while keeping those required for everyday activities, such as sending and receiving email, surfing the web, etc., open.

Like leaving your front door unlocked, leaving additional ports open increases the number of ways a person or program (like a worm) can walk in.

A router (a device used to share a DSL or cable connection with several computers or to make your internet connection wireless) should have its firewall to protect your network from outside threats. The fact that this firewall is built into a physical piece of hardware distinguishes it from software firewalls installed on individual computers.

While a router’s firewall is helpful, it is not sufficient protection for your computer; a software firewall is also recommended.

A software firewall is included in all modern versions of Windows (XP, Vista, and 7) and Mac OS (version 10.2 and later). Mac OS X and Windows versions before 8.1 do not. Any Windows installation after Windows XP Service Pack 2 should have the firewall on by default.

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The various forms of software firewalls:

Both “active” and “passive” firewalls can be considered broad categories of software firewalls.

A passive firewall does little more than sit there and close off the appropriate ports. However, an active firewall performs this function, monitors what’s happening on your computer, and allows you to decide which apps can leave.

Therefore, an active firewall can protect you against spyware that tries to “phone home” to report what information it has collected about you. As a result, you’ll be less vulnerable to harm.

Windows XP and Mac OS X’s firewalls take a hands-off approach.

Since no harmful apps are infecting Macs, there is a far lower risk for Mac users (at the time of recording, there are a tiny number of programs like this built for Macs, but they are not circulating or infecting machines). A firewall is essential on a Mac to prevent attacks from the outside world, albeit a passive firewall should suffice for the time being.

There are thousands of dangerous programs like worms, trojans, and spyware that, if installed on your Windows machine, will try to steal information without your knowledge.

Thus, you can unwittingly become a victim of so-called malware if you rely solely on a passive firewall like Windows’ built-in firewall.

What occurs is that malware infiltrates your system. Then either invites additional software in, opens a “back door” for someone to come in and snoop about, or steals your personal information and transfers it to unknown parties.

An operational firewall will also allow you to restrict which apps may send data out to the internet, not only which can enter.

If you have a passive firewall, it’s like closing the doors and windows to your house or business, making it far more difficult for an intruder to get access from the outside.

Unfortunately, the thieves are pretty cunning, so they slip someone inside when you aren’t looking, and that person hides somewhere, unlocks a door or window to let his buddies in, or looks through your stuff before handing them to someone outside through the window.

A firewall actively protecting your network is like having a security guard constantly patrol the premises and only letting in authorized individuals. If an intruder is discovered, he is detained until it is determined whether or not he poses a threat, and his hands are bound to prevent him from stealing.

Do you get what I’m saying?

What should you do now?

A firewall protects a computer from outside threats like hackers and harmful software. Without one, your computer is vulnerable to attack. A passive firewall is sufficient for Macs, but a Windows computer is still highly vulnerable due to the thousands of worms, viruses, spyware, etc.

Norton Internet Security (the term “internet security” refers to software that incorporates both antivirus and firewall protection) and Kaspersky Internet Security are two popular choices for Windows users.

Kaspersky Internet Security is my top choice because it is less well-known but has been around for many years and is quite reliable.

Windows’ built-in firewall isn’t enough to keep you safe, so disable it. Active firewalls do require some settings to block and allow apps properly.

The first time an application tries to connect to the internet, the firewall program will generally ask you if you want to allow or block it (and you can typically let it or prohibit it once or permanently).

You should always provide permission to programs like Outlook, Firefox, and others with a legitimate need to access the internet. The firewall will generally give you the name of the software it is questioning you about, allowing you to look it up on Google to see if it is legitimate.

If you search and receive many results about viruses or adware, you should probably block that site and see if you can have it cleaned up.

Little Snitch is a helpful utility for Mac users that require a higher level of protection than that offered by the OS X firewall. It’s a firewall that works, just like Zonealarm. The trial version of Little Snitch is available for free download.

A firewall is an essential tool for protecting your computer and its stored data. Don’t risk your computer’s health by operating without one.

Worth Godwin is a computer coach with over 15 years of experience assisting users of all skill levels with their computers. He has also spent significant time “in the trenches” as a hardware and software technician, resolving real-world computer issues.

Since the early 1990s, Worth has also investigated the mind and the learning process. He uses his background, education, and writing skills to explain things in a way that makes sense to students.

Worth started creating CDs with his short tutorials in 2006, and they can help you learn to use an Apple Mac or a Windows computer at your speed and within your budget.

linda