LECTURE 3 : NETTECH2

WHAT IS Firewall:

 firewall is a system designed to prevent unauthorized access to or from a private network. You can implement a firewall in either hardware or software form, or a combination of both. Firewalls prevent unauthorized internet users from accessing private networks connected to the internet, especially intranets.

What Are the Benefits of Firewall Security?

Monitors Traffic. A firewall monitors all of the traffic entering your computer network. ...

Blocks Trojans. A firewall helps block Trojan horses. ...

Stops Hackers. Having a firewall keeps hackers out of your network. ...

Stops Keyloggers. Having firewall security will reduce the risk of keyloggers monitoring you.

 

What Is the Purpose of a Firewall

 

The Firewall

A firewall is a piece of software that stands between a computer or network and the Internet. Connecting a computer directly to the global network is like leaving your front door open, allowing outsiders free access to your system. Any request will pass through to vulnerable systems, allowing unscrupulous third parties to exploit your computers for their own gain. A firewall serves to block these unauthorized requests, passing through only designated traffic.

Filtering

The primary purpose of a firewall is packet filtering. When a computer sends a request across the Internet, it takes the form of small packets of data, which travel through the network to their destination. The target server responds with its own packets of data, which return along the same route. A firewall monitors every packet that passes through it, considering its source, destination and what type of data it contains, and it compares that information to its internal rule set. If the firewall detects that the packet is unauthorized, it discards the data. Typically, firewalls allow traffic from common programs such email or Web browsers, while discarding most incoming requests. You can also configure a firewall to disallow access to certain websites or services to prevent employees from accessing non-work resources while on the clock.

Logging

Another important aspect of a firewall is its ability to log any traffic that passes through it. By recording the information from packets that pass through or that it discards, it can provide you with a clear picture of the kind of traffic your system experiences. This can be valuable in identifying the source of an external attack, but you can also use it to monitor your employees’ activities online to prevent lost productivity.

Internal Threats

While the primary goal of a firewall is to keep attackers out, it also serves a valuable purpose by monitoring outgoing connections. Many types of malware will send out a signal once they take over a system, allowing the author to trigger specific actions or even control the computer remotely. A firewall can alert you when an unknown program attempts to "phone home," alerting you to a possible malware infection and allowing you to shut it down before it causes major damage to your network. Heading off a malware attack before it activates will keep your employees productive, protect vital company data and save you the cost of cleaning up the problem with other security software.

Characteristics of a firewall ?

Ans :

Different protection levels based on the location of the computer

When your PC connects to a network, the firewall applies a security level in accordance with the type of network. If you want to change the security level assigned initially, you can do this at any time through the firewall settings.

Protection of wireless networks (Wi-Fi)

This blocks intrusion attempts launched through wireless networks (Wi-Fi). When an intruder attempts to access, a pop-up warning is displayed that allows you to immediately block the attack.

Access to the network and the Internet

It specifies which programs installed on your computer can access the network or the Internet.

Protection against intruders

It prevents hacker attacks that try to access your computer to carry out certain actions.

Blocks

The firewall can block the access of the programs that you specify should not be able to access the local network or the Internet. It also blocks access from other computers that try to connect to programs installed on your computer.

Definition of rules

This defines rules that you can use to specify which connections you want to allow and the ports and zones through which the connection can be established