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.