What is a Firewall?
A firewall is a network security system that monitors and controls the incoming and outgoing network traffic based on predetermined security rules. A firewall establishes a barrier between a trusted, secure internal network and another outside network, such as the Internet, that is assumed to not be secure or trusted. Firewalls are of two categories, i.e. networking firewall sand host-based firewalls.
Types of Firewall
Network firewall is applications running on general-purpose hardware or hardware-based firewall computer appliances that filter traffic between two or more networks. Host-based firewalls provide a layer of software on one host that controls the network traffic in and out of that single machine. The term firewall originally referred to a wall intended to confine a fire or potential fire within a building.
Function of Firewall
The primary function of a firewall is to stop redundant and uninvited incoming connections. Firewalls can block different types of connections intelligently e.g. they can allow access to network file shares services when your computer is connected to your home network, but not when it’s connected to a public Wi-Fi network.
By the launch of Windows XP SP2, Windows Firewall was upgraded and enabled by default; While Windows XP systems connected directly to the Internet became infected after four minutes on average. The Windows let the worms come in directly. Even if a modern version of Windows is vulnerable to such a worm, it will be extremely difficult to infect the computer because the firewall blocks all such incoming traffic. Today’s firewall was generated in three generations.
Three Generations of Firewall
- First generation firewall: The first type of firewall was the packet filter, which looks at network addresses and ports of the packet and determines if that packet should be allowed or blocked. If a packet does not match the packet filter’s set of filtering rules, the packet filter will reject it.
- Second generation: “stateful” filters: The second generation of firewalls was also known as Circuit-level gateways. They perform the same work as of first-generation but operate up to layer four (transport layer) of the OSI model. It records all connections passing through it and determines whether a packet is the start of a new connection, a part of an existing connection, or not part of any connection.
- Third generation: Application layer filtering:The key benefit of this is that it can “understand” certain applications and protocols such as File Transfer Protocol (FTP), Domain Name System (DNS), or Hypertext Transfer Protocol (HTTP). This is useful as it is able to detect if an unwanted protocol is attempting to bypass the firewall on an allowed port, or detect if a protocol is being abused in any harmful way.
So now you Understood all about Firewall, let us now discuss its viability.
Windows Firewall Support is Usually Good Enough:
The Windows Firewall does the same thing that a third party firewall does i.e. blocking of incoming connections. Third-party firewalls may pop up more often, informing you about various uninvited guests and demand your input, but the Windows firewall is constantly doing its thankless job by itself only. When a program wants to receive incoming connections, it must create a pop up and ask you for permission.
When You Would Want a Third-Party Firewall:
Windows firewall only does what is important, i.e. block incoming connections. It is made that way. However, it has some more advanced features, but they are in a hidden and hard to use and also it does not allow you to easily control which applications on your computer can connect to the Internet. It will not pop up a box when an application first initiates an outgoing connection.
While a third party firewall allows you to control which applications on your computer can access the Internet, blocking certain applications from connecting. This can be a little annoying, but it does give you more control. These firewalls are with loads of features. You can use a third-party tool to extend the Windows firewall, forcing it to prompt you for permission each time a new program wants to connect to the Internet.
Therefore, I should say that always enable your firewall support all the time as it does a thankless job all the time without expiration and no need any updating. It will be updated along with Windows itself. However, you also need a third party protection for more advanced worms, viruses and connections.
Latest posts by John Reynolds (see all)
- Introduction to Firewall and its Viability to User - October 6, 2015