Computer firewall

How Does A Firewall Work

If you have been using computers for the past few years, chances are pretty high that you would’ve come across the term ‘firewall’. Whether you use the internet at home or at the office, you would be aware of the cyber threats your network can face from malicious users or software.

But let’s make things a little clearer and start from the beginning

What is A Firewall?

A firewall is basically a wall that protects your network by filtering out content in outgoing and incoming traffic as per your (the user’s) settings and rules. A firewall is a security measure to prevent malware and suspicious unwanted content from entering your network, while allowing all legitimate data to filter through.

This is a layer of security that has become very commonly used in all homes and businesses, and acts like the first wall of defence against malicious cyber attacks.

Different Types of Firewalls

Firewall Shield

There are three types of firewalls:

1) Packet Filtering: Also known as Stateless, these packets check individual packets and so they only allow entry to your network based on individual packet headers, as they are not aware of the connection state. This means that as per pre-determined rules and filters, incoming information packets can be either flagged or allowed through, after which they are either forwarded to the systems or are discarded.

2) Stateful: This type of firewall is a lot more flexible than stateless firewalls as they have the ability to determine the connection state of all data packet. They work by collecting all similar packets before any firewall rule can be applied, until the connection state of the packets can be determined by the firewall.

3) Application: These are also more popularly known as proxy based firewalls and are the most effective at filtering data transmissions as they analyze all incoming and outgoing data, as per the firewall rules created for specific applications.

Why Would You Need a Firewall

  • Email Bombing – when someone sends you the same email consistently until your inbox is full
  • Remote login control – to avoid outside users from gaining control of your computer
  • Backdoor Applications – To filter out bugs that could provide hidden access to certain programs and unauthorized users
  • ​OS Bugs
  • ​DoS
  • ​Spam
  • Cyber Threats
  • Source Routing

How Can Firewalls Help Your Business

  • Large businesses and companies need complex firewalls to help keep their data secure.
  • Firewalls help to prevent computers from outside the network from accessing the devices inside the network.
  • ​Firewalls help to keep a check on the data that is sent by employees, so that no sensitive information is leaked outside of the network.
  • ​Firewalls help to prevent employees from accessing certain sites like social media networking sites.
  • ​They help in designating one computer to be a file sharing computer, while the rest of the computers connected to the network would be restricted from file sharing to keep data secure.
  • ​Multiple configuration settings are available whilst using firewalls for your business.
  • As businesses and large companies would have to utilise complex firewalls, advanced tech users and IT specialists would be needed to maintain and operate the advanced configurations of the firewalls.

How Can Firewalls Help Your Home Private Network

  • Firewalls for home networks are a lot simpler.
  • Most cyber threats targeting home networks look to illegally gaining access to confidential information for ID theft.
  • Cyber threats like viruses and other malware can damage your connected devices and computers and viruses remain the single most common problem in regards to your home computers. Firewalls help detect Trojan horse viruses, spyware and other malware which are transmitted over your internet connection to your network.

Firewall Customization

You can play around with the configurations of your firewall settings and can change filters according to certain factors.

IP Addresses: All devices connected to the internet will be allocated one unique address which is also known as an IP address. This is your unique identifier which will allow the data to be transferred effectively to the correct recipient on connected computers in a network. As this is your identifier, you can identify if there is an IP address not connected to your network that is accessing data from inside your network, and you can then restrict/ block access of all incoming and outgoing data to the IP address.

Domains: It’s not easy to remember a number, and most humans have a better chance at remembering domain names instead of numbers. IP addresses can change, due to different factors, but domain names tend to remain constant. A company or home network can block/ restrict traffic to certain domain names, or allow traffic to flow to only certain domain names.

Certain Keywords: You can customize your firewall to detect certain keywords or phrases in all incoming traffic. In a private home network, as an example, you could restrict data packets containing the words ‘Fluffy Unicorns’ and similar variations of the word to ensure that no content containing that keyword would filter into your network. That is just an example, the keywords depend on you. You will have to instruct your firewall to detect many variations of a certain keyword as your filter may not be able to detect symbols like _ or -.

Where are Firewalls Normally Found

These days firewalls come in built with your computers, laptops and other electronic devices. Many people who want additional security can opt for a software firewall which includes many popular antivirus brands today. These firewalls are either free at various websites or app stores, or premium versions can be purchased. The paid version would have updated, and better security settings than the free versions, which would offer only basic firewall.

Firewalls can also be found at the point of contact between your internet connection and your private home network. This would be in the form of your router. Containing a hardware firewall, these routers would be firewall units in themselves, and their settings can be configured to filter settings as per your requirements. Hardware firewalls are a very secure option for your home or business.

About the Author tomas

Hey, it's Tomas here! I'm the founder and chief editor here at BlueGadgetTooth. After spending hours explaining my parents how to hook up their Internet, why it's being so slow etc. I decided to start this blog to help people with their gadgets and questions about technology.