What is a Firewall and what does a Firewall do?
A firewall will stop malicious threats and hackers from accessing a network, or an individual computer. A firewall would monitor all traffic passing from the internet to the internal network, and would drop or allow traffic depending on how the rules are setup.
Getting to the point, a firewall will allow you to browse the internet and in turn will protect your computer from hackers, and malicious threats coming from the internet. There are two main types of Firewalls, as explained below;
Personal or Software Firewalls
A software firewall is a software application that is installed on a computer, which monitors and controls traffic to and from the computer. It is just like any other software product you install on a personal computer. When installed, the firewall will examine all traffic coming into and out of your personal computer.
As software firewalls require installing on the host (computer) itself, they can have a slight affect on the response time taking up memory and CPU power. However it is certainly a must having such a product. Well, it’s either this, or being exposed to the dangerous web of hackers and malicious software.
As the name implies, a hardware firewall is an actual hardware product. It’s usually shaped like a small flat plastic box, with network ports on the back, and an antenna if it has wireless connectivity.
The hardware firewall will plug into your modem using a network cable, and will also connect to your computer or computers. When internet traffic arrives through your modem, it passes the traffic along to your firewall which inspects the traffic and decides on rules whether to allow or disallow. If the traffic is ok, it will deliver it to the designated computer.
Network firewalls provide much more advanced security features than traditional home based firewalls. Traditional home based firewalls will provide NAT and stateful packet inspection, blocking everything inbound and allowing everything outbound, and that's about it. Network firewalls provide much more granular and powerful features required for businesses like application proxies, UTM features such as spam and web blocking, and other advanced features such as VPN's and VLANS.
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