What Is Firewall:
A firewall is a network security device that monitors incoming and outgoing network traffic and permits or blocks data packets based on a set of security rules. Its purpose is to establish a barrier between your internal network and incoming traffic from external sources (such as the internet) in order to block malicious traffic like viruses and hackers.
A firewall is a security device computer hardware or software that can help protect your network by filtering traffic and blocking outsiders from gaining unauthorized access to the private data on your computer.
Not only does a firewall block unwanted traffic, it can also help block malicious software from infecting your computer.
Firewalls can provide different levels of protection. They key is determining how much protection you need.
Importance of Firewall
The main 5 Benefits of Firewall are:
- Monitors Network Traffic: Data coming in and out of your systems creates opportunities for threats to compromise your operations. By monitoring and analyzing network traffic, firewalls leverage preestablished rules and filters to keep your systems protected.
- Stops Virus Attack: With hundreds of thousands of new threats developed every single day, it is vital that you put the defenses in place to keep your systems healthy. One of the most visible benefits of firewalls is the ability to control your system’s entry points and stop virus attacks.
- Prevents Hacking: With the rise of data theft and criminals holding systems hostage, firewalls have become even more important, as they prevent hackers from gaining unauthorized access to your data, emails, systems, and more. A firewall can stop a hacker completely or deter them to choose an easier target.
- Stops Spyware: As systems become more complex and robust, the entry points criminals can use to gain access to your systems also increase. One of the most common ways unwanted people gain access is by employing spyware and malware—programs designed to infiltrate your systems, control your computers, and steal your data. Firewalls serve as an important blockade against these malicious programs
- Promotes Privacy: By proactively working to keep your data and your customers’ data safe, you build an environment of privacy that your clients can trust. No one likes their data stolen, especially when it is clear that steps could have been taken to prevent the intrusion.
What Does Firewall do?
A firewall acts as a barrier or filter between your computer and another network such as the internet. A firewall acts as a gatekeeper. It monitors attempts to gain access to your operating system and blocks unwanted traffic or unrecognized sources.
It helps to protect your network and information by managing your network traffic, blocking unsolicited incoming network traffic, and validating access by assessing network traffic for anything malicious like hackers and malware.
Your operating system and your security software usually come with a pre-installed firewall. It’s a good idea to make sure those features are turned on. Also, make sure your security settings are configured to run updates automatically.
How Does Firewall Works?
To start, a firewalled system analyzes network traffic based on rules. A firewall only welcomes those incoming connections that it has been configured to accept. It does this by allowing or blocking specific data packets — units of communication you send over digital networks — based on pre-established security rules.
A firewall works like a traffic guard at your computer’s entry point, or port. Only trusted sources, or IP addresses, are allowed in. IP addresses are important because they identify a computer or source, just like your postal address identifies where you live.
Types of firewalls
There are software and hardware firewalls. Each format serves a different but important purpose. A hardware firewall is physical, like a broadband router — stored between your network and gateway. A software firewall is internal — a program on your computer that works through port numbers and applications.
There also are cloud-based firewalls, known as Firewall as a Service (FaaS). One benefit of cloud-based firewalls is that they can grow with your organization and, similar to hardware firewalls, do well with perimeter security.
There are several different types of firewalls based on their structure and functionality. Here are the different firewalls you can implement, depending on the size of your network and the level of security you need.
1. Packet-filtering firewalls
A packet-filtering firewall is a management program that can block network traffic IP protocol, an IP address, and a port number. This type of firewall is the most basic form of protection and is meant for smaller networks.
While packet-filtering firewalls can be helpful, they also have limitations. Because all web traffic is allowed, it doesn’t block web-based attacks. So, you need additional protection to distinguish between friendly and malicious web traffic.
2. Stateful multi-layer inspection (SMLI) firewalls
The stateful multi-layer inspection firewall has standard firewall capabilities and keeps track of established connections. It filters traffic based on state, port, and protocol, along with administrator-defined rules and context. This involves using data from prior connections and packets from the same connection.
Most firewalls rely on stateful packet inspection to keep track of all internal traffic. This firewall is a step above packet-filtering in its use of multi-layer monitoring.
However, it is still unable to distinguish between good and bad web traffic, so you may need additional software.
3. Next-generation firewalls (NGFW)
Next-generation firewalls are more sophisticated than packet-filtering and stateful inspection firewalls. Why? They have more levels of security, going beyond standard packet-filtering to inspect a packet in its entirety. That means not just the packet header, but also a packet’s contents and source. NGFW are able to block more sophisticated and evolving security threats like advanced malware.
4. Network address translation (NAT) firewalls
A NAT firewall is able to assess internet traffic and block unsolicited communications. In other words, it only accepts inbound web traffic if a device on your private network solicited it.
There are few disadvantages of having firewall as well:
Some of the disadvantages of having firewall are:
The main disadvantage of a firewall are:
1. that it cannot protect the network from attacks from the inside.
2. They often cannot protect against an insider attack.
3. Firewalls cannot protect a network or pc from viruses, Trojans, worms and spyware which spread through flash drives, potable hard disk and floppy etc.
4. They may restrict authorized users from accessing valuable services.
5. They do not protect against backdoor attacks.
6. They cannot protect the network if someone uses a broadband modem to access the internet.
