We have all heard the expression, “Fences make good neighbors.” I will build on that by saying that adding a Gate helps too as you may occasionally want to leave or invite a visitor in. A Firewall is just like a Fence around your home and you control who is allowed to pass through the Gate – both in and out. Although not impossible to break through the Fence it is much easier to pass through the Gate.
In the same manner, a Firewall is an added layer of digital protection around your Data (the information stored on your computer) that helps control who and what are allowed access. Think of a Firewall as an overly attentive Nanny or Parent. As a kid, you may have been allowed to play in the yard but not the street. Or, you could walk to school but not to the Mall and you were not allowed out after dark. These examples introduce the concepts of Firewall rules – what you are allowing your computer to do.
Put in a business context, you might restrict the ability for a computer (or your entire company) to only access Facebook during lunch hour or for one or two hours before or after business hours. At one client, there is a computer on the shop floor to make Labels. We set the Firewall to prevent all Internet access, as the job function does not require any Internet access.
Firewalls also keep unwanted intrusions out. Unless you are running a Network Server, there is almost no reason to allow any access to your computer from the Internet. If you are in a Small Office or Home Office network environment, you may share a folder on your computer (Public Folder) or share a Printer attached directly to your computer. In this case, Windows (and Macs) will open up the specific ports (doorways and gates) to allow the computers to share their resources. You can have different Firewall settings for Internal (Local) vs. External (Internet) networks at the same time.
We know for a fact that no computer operating system is perfect and they all have security flaws. A Firewall puts up an added layer of protection around the operating system so that the intruder cannot reach the operating system to exploit the Security Flaw.
Firewalls come in many flavors, such as Personal, Network, and Application, depending on what you are trying to protect. The important thing to understand is that the premise is the same: Set a specific rule to allow or disallow a specific activity or type of connection to or from a computer or your entire network.
The key differences between the Free Firewalls including with your computer operating system and the Paid Firewalls available as part of “Internet Security Suites” is the degree to which they automate the Rule creation function and what they monitor. For example, the Free Firewall included in Windows is predominantly a network port based Firewall. It will allow you to restrict or allow access to your computer or a network resource based on the specific network connection say (wired or wireless) and the protocol being used (Web Browsing, Port 80, or File Transfer, Port 21). If you look at a more comprehensive product like the ones included in Suites from Vipre, Kaspersky, Trend Micro, McAfee, or Norton they include Application Firewalls. These will monitor the specific activities of your Web Browser to make sure it is only going to “Safe” places. Or, if you have Quickbooks, the Application Firewall will alert you every time, (and allow you to set a rule), Quickbooks goes out to the Internet to get updates.
The more advanced Firewall products monitor every single attempt that your computer makes to access the Internet (or any outbound connection to a network resource – even to a network printer) and every attempt by something to access your computer (knock on your front door) and either block that access or allow you to “open the door and let them in.”
In general, the default settings of most Firewall products are sufficient if you mostly use your computer for Web Browsing, Email, and Document Creation activities. If you have specialized Line of Business applications (Accounting or Database), secure connections to remote or Corporate offices, or extensive File Transfer applications, you may need to adjust the Firewall Rules to allow these applications to operate properly.
The baseline for all of the Paid Companies is an Antivirus product. The addition of the phrase “Internet Security” usually adds a Firewall and the ability to monitor application activity and web-browsing to make sure that you are protected from accidentally visiting known malware and virus sites. Sometimes they add the phrase “Total Security” which may include the ability to monitor Chat and Instant Messenger sessions for transmission of viruses and other malware. In short, as each vendors solution increases in price, they add more and more security and monitoring features for different types of computer activities: email, chat, web-browsing, file transfer, etc.
Popular Internet Security Suites
NOTE: These are the Consumer Product Listings – Equivalents Exist for Business
Vipre Internet Security
Kaspersky Internet Security
Trend Micro Titanium Internet Security
McAfee Internet Security
Norton Internet Security