In this tutorial we will have a glance to “Cyber Security System Firewalls” and learn how they secure your data and computer. Firewalls initially were incombustible walls used as barriers to prevent fire from spreading, such as between apartment units within a building.
The same term is used for systems (hardware and software) that seek to prevent unauthorized access of an organization’s secret information. Firewalls are like security guards that, based on certain rules, allow or refute access to/from traffic that enters or leaves an organization (home) system.
They are important systems safe guards that seek to prevent an organization’s system from being attacked by internal or external users. It is the first and most important security gate between external and internal systems.
Firewalls are generally placed between the Internet and an organization’s information system. The firewall manager configures the firewall with rules allowing or denying information packets from entering into or leaving the organization.
The rules are made using a combination of Internet Protocol (IP) address and Ports; such rules are made depending on the organization needs e.g. in a school, students are allowed in based on identity card.
The rule to the security guard in a school would be to allow all persons that carry a valid identity card and deny everyone else. However the security guard would have another rule for exiting from the school; the rule would be to allow everyone exit except small children unless accompanied by adults. A similar system is followed for firewall configuration depending on the nature of the organization, the criticality of information asset, cost of security, security policy and risk evaluation.
The firewall just like a security guard cannot judge the contents of the information packet; just like the guard allows all persons with a valid identity card irrespective of nature of the persons, firewall allows entry or exit based mainly on IP address and Port numbers. Hence an entry or exit is possible by masking IP address or Port.
There are a range of kinds of firewall depending on the features that it has viz. packet filter (operates on IP packets), stateful firewall (operates based connection state) or application firewall (using proxy).
Example of a firewall rule could be: Block inbound TCP address 220.127.116.11 from port 124. (An imaginary example); such rule would tell a computer connected to Internet to block any traffic originating from the computer with an IP address 18.104.22.168 using Port 124.
Important activities relating to firewalls are initial configuration (creating initial rules), system maintenance (additions or change in environment), review of audit logs, acting on alarms and configuration testing.
That’s how firewall works and protects your daily computer life 🙂