Which of the following functions does a computer firewall perform?

Hello again at this meeting we will discuss about firewalls.

A firewall is a system specifically designed to prevent suspicious access from entering a private network. Firewall itself can be hardware or software, it can also consist of a combination of both.

Firewall (fire retaining wall) itself is actually inspired by a physical object called a firewall that is installed in buildings to prevent the spread of fire from its source. Firewalls for many buildings are installed, for example in apartment complexes. To separate the two apartment units, a firewall was installed so that in the event of a fire the fire does not quickly spread from one unit to another.

Because the firewall serves as a barrier to the outside world, then for one apartment unit that has four sides, for example, it must install a firewall at all four border points. If one side is not limited by a firewall while the other three are fitted with a firewall, it will be futile to try to hold back the fire that will spread quickly. So is the case with firewalls for computers.

In order to function effectively, a firewall must meet certain standards, be able to establish a ‘security fence’ around a private network, prevent unauthorized access and various disruptions to documents or files on the user’s computer. On the market, there are quite a number of firewall products offered with varied functions. The difference between firewalls with one another is usually in how tight the security and selectivity of access, and the scope of protection at various layers of the OSI (Open System Interconnection).

firewall function.

Firewall itself has several functions to protect computer networks that can be described in the following points:

1. As a Network Security Post. All traffic that enters or exits the network must go through a firewall as a security post that will conduct an inspection. Every time a traffic occurs, the firewall will try to filter the traffic in accordance with the security that has been determined.
2. Prevent valuable information from being leaked without knowing. For this one function, many firewalls are installed for File Transfer Protocol (FTP), so that every data traffic is controlled by a firewall. In this case, a firewall is useful to prevent users on the network from sending valuable confidential files to other parties.
3. Record User Activity. Every time you will access data, network users will go through a firewall which then records it as documentation (log files), which later records can be opened to develop security systems. Firewall is able to access log data while providing statistics on network usage.
   Modifying the Coming Data Package. Also known as NAT (Network Address Translation). NAT is used to hide an IP address, so that users can access the internet without a public IP address, which is often also referred to as IP masquerading.
4. Prevent Modification of Other Party Data. For example in business matters for financial statement information, product specifications, and others that are company secrets and will have a negative impact if known to other parties. Firewall prevents modification of these data so that they remain safe.

How Firewall Works

Basically, firewalls work by limiting personal computers to the internet. Firewalls work like security guards in front of the house gate and identify visitors who come, while filtering intruders trying to enter a personal computer. Firewalls work like the foremost defense guard to resist any hacking attempts that enter the computer.

Firewall technology is increasingly growing. Previously, the firewall worked to filter computer traffic using IP addresses, port numbers, and protocols. Along with its development, now the firewall is able to filter incoming data by first identifying the content message it carries. To manage the traffic of computer and internet data transfer, a firewall can use one or a combination of the following methods:

1. Packet Filtering

It is a way of working a firewall by monitoring incoming and outgoing packages, allowing it to pass or hold on based on its Internet Protocol (IP) address, protocol, and port. Packet filtering is usually quite effective to use to withstand attacks from a LAN. Packet filtering is also called a static firewall.

During communication with the internet network, packets that come are filtered and matched with rules that have previously been made in building a firewall. If the data is suitable, then the data can be received and vice versa if it does not match the rules, then the data is rejected.

In the packet filtering method, the firewall checks the source and destination of the IP address. The packet sender may use different applications and programs, so the packet filtering also checks the source and destination of the protocol, such as UDP (User Datagram Protocol) and TCP (Transmission Control Protocol).

2. Stateful inspection

Contrary to Packet Filtering, Stateful Inspection is also known as a dynamic firewall. On stateful inspection, the active status of the connection is monitored, then the information obtained will be used to determine whether a network packet can penetrate the firewall.

Stateful inspection on a large scale has replaced packet filtering. On a static firewall, only the header of the packet is checked, meaning that a hacker can retrieve information through a firewall with a simple, that is, indicate “reply” through the header.

While with a dynamic firewall, a packet is analyzed into its layers, by recording the IP address and port number, so that security is tighter than packet filtering. So that’s a discussion about the notion of firewalls, firewall functions, and how firewalls work. May be useful.