Definition of Firewall: Types, Functions, and Working Mechanisms. A firewall is a security system that functions to protect networks and computers from external threats such as virus attacks, malware, or hackers.
Definition of Firewall
In computer networks, a firewall is a security system that functions to protect networks and computers from external threats. The firewall works by analyzing incoming and outgoing data traffic and filtering information that enters the network. The firewall can also monitor and control access to the network or the Internet, as well as identify and prevent attacks from viruses, malware, or hackers. In the firewall configuration, network administrators can determine the allowed or blocked access rules and identify the types of data traffic that can pass through the firewall. Firewalls can be placed at various points in the network, such as between the router and the Internet, between servers and the local network, or on user computers.
Types of Firewalls in Computer Networks
The following are types of firewalls in computer networks:
- Firewall Packet Filtering: This type of firewall is the simplest and most commonly used. This firewall allows or blocks data packets based on IP address, protocol, and port number. The advantage of this firewall is that it is easy to configure, but its weakness is that it is difficult to identify and block more complex attacks.
- Firewall Circuit-Level Gateway: This firewall works at the session level and only checks whether the session is valid or not. This firewall does not check the contents of data packets and only allows data traffic from verified sessions.
- Firewall Application-Level Gateway: This type of firewall is also known as a proxy firewall. This firewall checks every incoming and outgoing data packet and can determine whether the packet is safe or not. This firewall is more secure than a packet filtering firewall, but also requires more resources.
- Firewall Next-Generation Firewall (NGFW): This type of firewall is more advanced than conventional firewalls. NGFW is able to inspect the contents of data packets and determine whether the packet is safe or not. This firewall can also analyze data being processed and block more complex attacks, such as zero-day attacks.
- Firewall Stateful Multilayer Inspection (SMLI): This firewall can evaluate data traffic on multiple layers, such as OSI Layer 3 and OSI Layer 4. This firewall can also analyze the flow of data being processed and check incoming and outgoing connections from the network.
- Firewall Hardware: This type of firewall is a hardware device designed specifically for firewall purposes. Hardware firewalls are more advanced than software firewalls and are usually equipped with additional security features such as antivirus, anti-spam, and anti-malware.
Each type of firewall has its own advantages and disadvantages. Therefore, before choosing the type of firewall to be used, security analysis and evaluation of the network needs to be implemented.
Functions of Firewall in Computer Networks
The main function of a firewall is to control incoming and outgoing data traffic from a computer network, so that only allowed data traffic can pass through the firewall and enter the network. In addition, the following are some of the functions of firewalls in computer networks:
- Blocking attacks from outside the network: Firewalls can identify and block attacks that originate from outside the network, such as DDoS attacks, port scanning, and hacking attempts. Firewalls can do this by checking the sender’s IP address and applying predefined rules.
- Preventing malware from entering the network: Firewalls can check data traffic entering the network and check files or applications that will be downloaded by users. Firewalls can block files or applications suspected of containing malware or viruses, thus preventing malware from entering the network and infecting other devices.
- Controlling user access: Firewalls can limit user access to certain network resources, such as servers or databases. This can be done by applying access
The Advantages and Disadvantages of using a Firewall in Computer Networks.
Advantages of Firewall
Protects the network: A firewall can protect the network from unwanted attacks such as viruses, malware, and hackers. It helps to control and restrict access to the network and provides additional protection for devices connected to the network.
Monitors data traffic: A firewall can monitor data traffic and track all incoming and outgoing information from the network. This way, the firewall can detect suspicious activity or malicious attacks and alert the network administrator.
Improves network performance: A firewall can improve network performance by blocking unnecessary traffic. This way, the firewall helps to ensure that the network runs smoothly and does not experience slow performance due to excessive traffic.
Manages internet access: A firewall can restrict access to unwanted websites and applications. This helps to maintain network performance and prevent unproductive or dangerous internet use.
Disadvantages of Firewall
Cost: Firewalls can be expensive to implement, especially if a company chooses to use expensive hardware devices.
Performance: Firewalls can affect network performance and can slow down data traffic if not properly configured.
Dependence on administrators: Firewalls require highly trained and qualified administrators to operate and maintain these devices. If a company does not have qualified administrators, then the firewall may not function well and may not provide optimal protection.
Not always effective: Although a firewall can help protect the network, there is no guarantee that the device will always be effective. A clever attack can bypass the firewall and damage the network, even if the firewall is installed and functioning properly.
Writer : Hassan Rizky Putra Sailellah
Editor : Meilina Eka Ayuningtyas
