Firewall – Why do you need it!


Table of Content

1. Why do you need a Firewall?

2 . What is a Firewall?

3. How do Firewalls work?

4. Firewall and VPN

Why do you need a Firewall?

If you use a common operating system, it’s likely that you also utilize a firewall. They’re an important part of everyday security for your home and office. In fact, many systems utilize more than one firewall – operating systems, routers, and other devices you use to connect to the internet, all have firewalls automatically installed.

Why are they so common? Firewalls are an essential part of basic security. They function like a typical wall. They keep unwanted traffic away, while protecting the information inside. If you’re unfamiliar with how a firewall works and how, let’s say, an office can block specific sites from being viewed, a quick refresher is in order.

What is a Firewall?

A firewall is a simple data filter for connections to your computer or router. Sometimes the filter is for viruses and unwanted programs and data. Sometimes the filter can be for inappropriate sites and social media, to increase productivity at work. There are a few ways the administrator of a firewall can restrict information.

Domain Names

Domain names or internet addresses are unique identifiers for specific websites. By blocking the domain in the firewall, users will be unable to access the site. This is especially handy for blocking social media at work or at home.

Protocol or Ports

Blocking protocols or ports is a little different than blocking a domain. When you access the internet you use a variety of ports like HTTP, HTTPS, Etc., Some of these ports are not commonly used for daily web browsing and business transactions. These are ports like TelNet which blocking will stop common hacking attempts. Other ports like FTP leave your computer vulnerable to file transfers containing malware, and are best closed until needed.

 IP Address

An IP address is a specific location and designation for an internet user. The ability to block an IP is useful if you detect malicious traffic from a specific IP address, or to stop harassment from a specific user.

How do Firewalls work?

Once you understand what a firewall does, understanding how it works becomes much easier. Since a firewall works as a gateway and a security check all in one, it applies the rules you have set for information to each individual piece of information that passes through the gateway. This information is typically stored in packets, where the information is stored inside with identifying information on the outside of the packet. The firewall checks each packet for IP address, content, location, and file type – if the packet shouldn’t be allowed, the firewall drops the packet without damaging your computer.

There are several ways firewalls accomplish this:

Packet Filtering: Packet Filtering inspects each packet the same, regardless of the location of the information or the program using the data.

Application-layer Filtering: Application filtering is more detailed and advanced than simple packet filtering. Instead of treating all packets the same the filter looks for which application the packets correspond to. This way information can be better filtered based on intent and use. This allows administers of firewalls to stop specific programs from working like file sharing.

Stateful Inspection: Your firewall will check each packet and also the network connection the packet is traveling from. Allowing the firewall to process the packets much faster in larger batches. Most modern modems use this model.

Choosing the right firewall is important, since firewalls are so crucial to filtering traffic.

Firewall and VPN

If you desided to use firewall it is important to use VPN provider with the NAT Firewall option included as VPN connection usually bypasses your router’s firewall you will need extra one inside it. Lime VPN always includes NAT Firewall as VPN feature to any VPN subscription plan.