Regardless of the size of a business, firewalls are a necessity for guarding against those that wish to penetrate a company’s system in order to steal information. There are several different types of firewalls and different manufacturers that produce them. Being empowered with the knowledge of how to choose the correct firewall for a business network is crucial. This guide will cover what a firewall is, how to choose one for a business, and the different types of firewalls one can choose. Utilizing the information provided here will help save time and money.

"Firewall" was a term originally used to refer to a wall meant to contain a fire within a building to keep it from spreading and to protect important areas of the building. This term is also used to refer to other structures, such as metal sheeting that separates an engine compartment of a vehicle or aircraft from a passenger compartment.

The current computer firewall technology came about in the late 1980s when the Internet was just getting its start and growing in popularity in terms of the global use and connectivity. The original firewalls used for network security were routers used in the late 1980s. Just like historical firewalls, today’s business network firewalls are designed to keep the network safe from those who would harm it.

The job of a firewall is to keep a network secure. The main work of a firewall is the control of incoming and outgoing traffic on the network. This is done based on a set of rules for how data packets are handled by the network and whether they will be allowed through. A firewall is either software-based or hardware-based. It acts as a bridge between the business’ internal network and an outside network such as the Internet, which is usually not as secure. In a business network situation, the security of the network as it interacts with the Internet and outside users is of paramount importance. Although many operating systems come with some kind of software-based firewall installed, it’s necessary to consider greater protection for most business networks. This is accomplished through several types of firewalls.

There are six basic types of firewalls which can be used in a business network setting to secure the information and access of users both inside and outside of the network which are listed here along with a brief description of each:

Always keeping in mind that numbers of users are the key to choosing the right firewall, this list should help simplify the process.

There are many things that a buyer should think about when considering which firewall solution to use to protect a business network. It is important that the buyer look at each one before choosing.

There are two main types of firewalls available. The first is called SOHO (Small Office, Home Office) and the second, and more expensive, is called an enterprise class firewall. In order to determine which type works best for the business, a buyer needs to assess how many users will be using the network. The more users, the higher class of firewall needed. Of course, even with only one user, a business could still utilize an enterprise class firewall; however, it could be more costly and include features that aren’t needed.

A SOHO firewall can usually accommodate up to fifty users without too much trouble. If it’s anticipated that there will be more than that, buyers may want to move up to the enterprise class firewall to keep from overloading the network and creating holes through which individuals can penetrate the business.

When taking into account the number of users to be accessing the network, a business needs to understand that the number of users also affects how much RAM and processing power is needed in the firewall to be used.

RAM, or random-access memory, is the most common type of memory found in a firewall or computer. Choosing the correct type of RAM is extremely important as this will directly affect how compatible a firewall is with the computer system. The following two types of RAM hold the most importance when choosing a compatible firewall:

This refers to the main type of memory used in a computer. DRAM needs to be refreshed every so often as it has a limited amount of storage capability.

This refers to a secondary (yet still common) type of memory used in a computer. SRAM differs from DRAM in that it does not need to be refreshed, and cycles through memory a lot faster.

Most firewalls will be compatible with DRAM or SRAM depending on the memory needed. A small number of users on a network can function with a lower amount of RAM such as DRAM. However, should a business have an extensive number of users, it is important to look into investing in memory with a higher capacity like the SRAM. Choosing the correct one can increase a business’ productivity while enabling the firewall to work efficiently.

Most all widely used firewalls come packaged with network address translation, or NAT. NAT affords a business the capability to translate illegal or private IP addresses into legal public addresses and in turn, it helps to protect the internal anatomy of the network from prying eyes.

There are four different types of NAT configurations that a company should be mindful of when choosing a firewall. They are listed below:

Making sure to choose the right NAT will stave off unnecessary issues regarding addressing.

A VPN allows users to access site-to-site encryption. Firewalls are often used as VPN endpoints, but only some firewalls come with VPN capabilities. A firewall blocks traffic and only allows certain things in or out. However, once the information is on the Internet, it is pretty much accessible to the world. In order to ensure the business’ privacy and retain the data’s integrity it is helpful to utilize a VPN. Should a buyer decide that a VPN is the best route, they should keep in mind that a VPN requires two endpoints. If there are not two endpoints in use, a VPN is rendered useless.

Below is a table which depicts the amount of RAM suitable for the number of users along with other variables including the number of offices, and packet filtering requirements. This should help in sizing the firewall for the business.

By using the above table, buyers can make an informed choice about the right firewall for their particular business network needs.

There are, of course, a large variety of firewall manufacturers; however, to narrow it down and give buyers an idea of some of the more noteworthy producers of business firewalls, here is a list of the top four manufacturers:

This list should help in having a better understanding of how to apply the knowledge provided here in the actual buying process.

Once you’ve decided which firewall will work best for your business, it’s time to begin the search for that specific product. eBay is an excellent source in which to find vendors for your firewall and you can use the following information to help in the purchase of your new software or hardware:

You can begin your search using the search bar on the home page. Another option is to use the Advanced Search also available from the home page. If you would prefer to browse through different categories, you can follow these simple steps:

Begin by choosing Electronics from the home page selection. Next, you will want to navigate to Computers, Tablets and Networking, then to All Categories. This will pop up another screen enabling you to choose from a larger variety of subjects. Here, you will want to click on Enterprise Networking, Servers and finally on Firewall and VPN Devices. At this point, you can choose from a few options if you wish to narrow down the type of firewall you are looking for, otherwise you can browse through the selection available.

To conclude this guide, let’s take a look back at the basics of how to choose the right firewall for a business network. Taking into account the number of users is the most important factor, as this affects all other decisions made regarding the product. Next would be to decide whether you need a SOHO or enterprise-class firewall, and from there it’s a simple fact of cost versus need.

Much of the time, this malware piggybacks on other programs, file downloads, or email, just as viruses do. Since the user gives permission for this data to be downloaded to the computer, malware programs are very difficult to detect before they get into the computer. However, they can be detected once they are installed.

Another long-standing problem on the Internet is hacking. Hackers have existed since before the Internet, seeking ways to get into computers and access information. While most hackers break into computers purely as a game, to prove that they can do so, there are those who hack into computers to steal information, ideas, or even money.

Since some hackers develop programs that do their work for them, going around the Internet to snoop into computers and see what they can find, the line between hacking and malware is a fine one. In either case, these are things that we do not want on our computers.

Firewalls exist to protect a computer from hackers, and to a lesser extent, from malware. It is important to note that firewalls cannot protect a computer from viruses. One must have virus detection software installed as well, and run regular scans of the computer. Most virus software can be configured so that it will run these scans automatically, with minimal user input.

Firewalls come in two types, hardware and software. In reality, the hardware ones have software inside that actually does the work. However, they are referred to as hardware firewalls because they are a separate box, rather than a program installed in the computer.

There are three types of architecture used for firewalls. To clarify, the term "architecture" refers to the collection of hardware and software components and their interfaces, which work together to create a functioning system.

Stateful inspection actively examines the state of any active network connections. Based on this information, it determines which packets of information to accept and which ones to reject. This provides the highest level of intrusion protection of any firewall, along with the highest level of access control.

Proxy firewalls require the use of a proxy server in the Internet cloud. The user’s computer acts as a proxy client, requesting information or resources from the proxy server, rather than from the actual website or computer. Once the proxy server verifies the request, it makes the request to the website or server. It is typical for proxy servers to provide detailed logging and password access protection to help maintain security.

The extra steps that a proxy firewall requires slow down the connection and retrieval of any information. For this reason, they are not very widely used. However, they are highly secure.

Packet filtering is the simplest and least secure form of firewall. It works by examining the header of packets of information and allowing or disallowing them to pass, based on pre-programmed or user-defined rules. A common rule is to only allow packets of information that have been requested from a remote location by a computer on the local area network (LAN).

A hardware firewall is a black box which sits on the upstream network line, protecting everything on the network. In a business environment, this allows the firewall to protect a department’s LAN from intrusion by other departments. In the case of departments which have sensitive information, such as the accounting department or human resources, this provides an extra layer of security for that data and the company overall.

These firewalls work by packet filtering, so they cannot catch everything. However, they cannot be easily defeated by malware, some of which directly attacks software firewalls. Since they are not installed on any computer, they do not slow the computers down by taking up system resources.

Many network routers have built-in firewalls. This helps reduce the cost by eliminating the need to buy a separate firewall. However, standalone hardware firewalls do exist, and are typically more robust in their protection than those which are internal to the router.

The major disadvantage of a hardware firewall is that they are harder to configure, especially for a novice computer user. In addition, they treat everything outgoing from the computer as if it is safe. This can cause problems in the case of some types of malware, such as trojans which try to connect to the Internet from the computer that they infect.

When anyone disconnects their computer from the network and connects through an alternate Internet access point, such as when traveling, they lose the protection that the hardware firewall provides.

Software firewalls are programs installed on a computer to catch malware and hackers. They work by residing between the computer’s software and the network connection, examining everything that goes in or out to determine if it is a valid request. As such, they can often catch malware, whereas hardware firewalls cannot.

This type of firewall does use system memory, processing time, and other resources. Therefore, it can slow down a computer’s general operation and especially the computer’s Internet communication. When shopping for software firewalls, it is important to compare how much system resources they require.

Software firewalls are much easier to configure than hardware ones and can be individually configured by the user. With a few mouse clicks, the level of firewall protection can be customized to the individual user’s preferences and needs. The highest level of protection would include blocking all cookies and JavaScript; however, it should be noted that this will prevent some web pages from functioning.

With a software firewall, the user can define which programs have permission to access the Internet. When set up in this manner, any other programs which try to access the Internet, such as malware, are automatically blocked. Since these firewalls reside in the computer, they are highly portable, going wherever the computer goes.

The biggest disadvantage of software firewalls is that they do use up some system resources. While well-written firewall programs use a minimum amount of system resources, others can use enough to severely reduce system operating speed. In addition, each computer must have its own copy or license for using the firewall. In a large company, this can be costly.

Deciding between buying a hardware firewall and a software firewall is mostly an issue of comparing the two and determining which will work best for one’s particular application. Each has its own advantages and disadvantages. Let us summarize:

This chart makes it rather clear that neither option is perfect. Rather, most networking security experts recommend installing both hardware and software firewalls on a computer for the best possible security. This way, computers are protected both while on the network and when away from the office.

Both hardware and software firewalls are available for sale on eBay. To find hardware firewalls, start from the Electronics area of the main eBay navigation menu. From there, select <a data-cke-saved-href="Tablets" href="Tablets" and="" networking"="">Computers, Tablets and Networking. Once on the main "Computers" page, select "All Categories" from the navigation menu to open up the detailed navigation pop-up. Find the category Enterprise Networking, Servers and then the subcategory Firewall and VPN Devices . From this page, you can select the Firewallfilter to eliminate the VPN devices.

VPN stands for Virtual Private Network. It operates similar to a proxy firewall. So, in a sense we can refer to a VPN as a type of firewall.

Software firewalls are found in the software section of the computer area. To find them, start the same way as to find hardware firewalls. In the detailed computer navigation pop-up menu, find the category Software, and then look for the subcategoryAntivirus and Security. Once on this page, use the Firewall Software filter to filter out the other types of security software.

With the high risk inherent in connecting to the Internet today, having a firewall is essential. Between malware, hackers, and those practicing identity theft, the need to protect any computer is acute. Firewalls and antivirus software are both essential parts of this protection.

The debate goes on about whether hardware or software firewalls are better. Each has its advantages, which are often weaknesses in the other type of firewall system. Most computer security experts say that it is best to install both types of firewall, hardware and software, to ensure the best possible protection.

Firewalls will not catch viruses or even all types of malware. In addition to a good firewall, it is important to have good virus-scanning software. Most companies that offer this software do so on an annual contract basis, allowing the licensee unlimited free upgrades throughout the year. This is an important feature, as these packages are constantly being upgraded as new virus and malware threats are discovered.