Working of Firewall

What is Firewall?

A firewall is a network security device, either hardware or software-based, which monitors all incoming and outgoing traffic and based on a defined set of security rules accepts, rejects, or drops that specific traffic....

History and Need for Firewall

Before Firewalls, network security was performed by Access Control Lists (ACLs) residing on routers. ACLs are rules that determine whether network access should be granted or denied to specific IP address. But ACLs cannot determine the nature of the packet it is blocking. Also, ACL alone does not have the capacity to keep threats out of the network. Hence, the Firewall was introduced. Connectivity to the Internet is no longer optional for organizations. However, accessing the Internet provides benefits to the organization; it also enables the outside world to interact with the internal network of the organization. This creates a threat to the organization. In order to secure the internal network from unauthorized traffic, we need a Firewall....

Working of Firewall

Firewall match the network traffic against the rule set defined in its table. Once the rule is matched, associate action is applied to the network traffic. For example, Rules are defined as any employee from Human Resources department cannot access the data from code server and at the same time another rule is defined like system administrator can access the data from both Human Resource and technical department. Rules can be defined on the firewall based on the necessity and security policies of the organization. From the perspective of a server, network traffic can be either outgoing or incoming....

Types of Firewall

Firewalls can be categorized based on their generation....

Functions of Firewall

Every piece of data that enters or leaves a computer network must go via the firewall. If the data packets are safely routed via the firewall, all of the important data remains intact. A firewall logs each data packet that passes through it, enabling the user to keep track of all network activities. Since the data is stored safely inside the data packets, it cannot be altered. Every attempt for access to our operating system is examined by our firewall, which also blocks traffic from unidentified or undesired sources....

Advantages of using Firewall

Protection from unauthorized access: Firewalls can be set up to restrict incoming traffic from particular IP addresses or networks, preventing hackers or other malicious actors from easily accessing a network or system. Protection from unwanted access. Prevention of malware and other threats: Malware and other threat prevention: Firewalls can be set up to block traffic linked to known malware or other security concerns, assisting in the defense against these kinds of attacks. Control of network access: By limiting access to specified individuals or groups for particular servers or applications, firewalls can be used to restrict access to particular network resources or services.  Monitoring of network activity: Firewalls can be set up to record and keep track of all network activity. Regulation compliance: Many industries are bound by rules that demand the usage of firewalls or other security measures. Network segmentation: By using firewalls to split up a bigger network into smaller subnets, the attack surface is reduced and the security level is raised....

Disadvantages of using Firewall

Complexity: Setting up and keeping up a firewall can be time-consuming and difficult, especially for bigger networks or companies with a wide variety of users and devices. Limited Visibility: Firewalls may not be able to identify or stop security risks that operate at other levels, such as the application or endpoint level, because they can only observe and manage traffic at the network level. False sense of security: Some businesses may place an excessive amount of reliance on their firewall and disregard other crucial security measures like endpoint security or intrusion detection systems. Limited adaptability: Because firewalls are frequently rule-based, they might not be able to respond to fresh security threats.  Performance impact: Network performance can be significantly impacted by firewalls, particularly if they are set up to analyze or manage a lot of traffic. Limited scalability: Because firewalls are only able to secure one network, businesses that have several networks must deploy many firewalls, which can be expensive. Limited VPN support: Some firewalls might not allow complex VPN features like split tunneling, which could restrict the experience of a remote worker. Cost: Purchasing many devices or add-on features for a firewall system can be expensive, especially for businesses....

Frequently Asked Question on Firewalls – FAQs

Can Network Speeds Be Slowed Down by a Firewall?...