Network Basics: How do Firewalls Work?

firewalls working on any electronic device

Firewalls, in networking terms, refers to a program that keeps unwanted sources from coming in, and out, from your computer network. In a sense, the firewall used for computers, and the firewall that is installed in buildings, have similar purposes; except one is physical, while the other is not.

Imagine the network as individual rooms. Each room has different furnishings, electrical appliances, and people within them, and just like real life, you can’t control what comes in or out of these rooms. Now, imagine a fire starting in the room 3 doors down from your own; the fire is hungry, and immediately engulfs anything it touches. The possibility of the fire consuming the next following rooms near your own is a potential threat; this is where the firewall comes in. If a firewall is installed in each of the rooms, it is highly unlikely that the fire will make contact with the other rooms because it is difficult for the flames to pass through.

Viruses, and doubtful sites, are like these fires; they circulate within the infinite spaces of the internet. When you enter the internet, and begin clicking one link after the other, chances are that at least one of those links contains a virus which may harm your hard drive. Computer viruses and non-trustworthy sites are capable of slowing down your computer system, deleting files, acquiring your personal information (by hacking into social networking sites like Facebook), and corrupting the internal software of your computer. Rebooting, and reformatting, your computer are two ways which can “delete” these unwanted programs; by doing so, however, would mean that all your unsaved files and programs will disappear, as well, and you will have to go back to square one. Installing firewall programs will save you time, effort, and money when dealing with the unwanted software.

Firewalls and antiviruses are two very different programs. Antiviruses detect harmful programs which can compromise your computer; enabling you to delete these programs with their software. Firewalls monitor network traffic, and alarms you if the site you are about to enter is safe or not.

Different Types of Firewall

  • Packet filtering: Packet filtering examines the data that enters and leaves your network. Following the rules based by the user, it accepts or rejects the data that passes through. It is an effective software, and transparent for the user, but it is also difficult to configure.
  • Circuit-level gateway implementation: This firewall does not need to be continuously checked; the data that enters or exits your network easily flows through this system. It applies a security mechanism when a connection is established within the process.
  • Proxy Servers: With this firewall, your true networking address is hidden, preventing the computer(s) you are connecting to from seeing it. It connects to the internet, and makes requests for pages, and connections to other servers. Proxy servers, however, may slow down your network performance, and only allow certain types of data to pass (e.g, HTTP files, or web pages.)
  • Web application firewall: Web application firewalls are plug-in hardware appliances, or other software filters that apply rules to a HTTP conversation. They are generally customized so that many attacks can be blocked and identified.

Software, such as the firewall, are necessary systems to put in your computer. It keeps unwanted data out, and prevents your data from ever leaving your system.

Here at LeBlanc Communications, we offer next generation firewalls for your networking protection needs. Through our maintenance and support assistance, our customers will benefit from our many installation services such as office cameras, Wifi, and IP phones; making it easier and safer for you to connect with the world.

If you live in or near Norwalk or Greenwich, Connecticut and are interested in our services, please contact us by dialing: 203-938-8400. You may also visit our contact page to learn more.