In the event of an emergency, the firewall is used as a wall to block the fires. A network firewall is used to set a barrier between the internet and LAN (local area network). The purpose of a network firewall is to protect our private LAN. It is used to save our important data from leaking out. Without the firewall capability, the routers will blindly pass traffic between two different networks. A firewall is used to monitor the traffic and block the traffic, which is not authorized to go out. A network firewall separates the internet and the LAN. In the LAN, it also segments the ordinary data and the important data. Due to this, the internal invasion can be avoided. You will determine the amount of threats that are blocked by your firewall. By blocking, firewall prevents your private network from outside users. You need to create a Demilitarized Zone (DMZ) if you allow remote access from others to your network. Most of the firewall provided the DMZ option. It will designate a directory on the computer of a gateway, just like Demilitarized Zone. Virus protected is offered by some firewalls. It is recommended for every computer to install the anti-virus.
Working of Network Firewall
Some hardware firewalls allow you to define the blocking rules like UDP (User diagram protocol) or TCP (transmission control protocol) or by IP address. This helps you to forbidden the IP address and unwanted ports. Software applications and services define some other type of firewall. Such firewall acts like a proxy server, which is used to interconnect the two separate networks. The combination of a software firewall and a hardware firewall is more efficient and safer.
Importance of Firewall
- Using the firewall, you can protect your home computer. To protect your network, you should use a hardware firewall if you have more than one computer. You should follow the policy of the network administrator if you are using a public computer.
- A firewall is designed to protect the organization from cyber-attacks. Many internal programs that have potentially exploitable can be protected by firewall from danger by limiting the traffic that crosses the boundary of the network, which is available only for authorized traffic.
- A firewall provides you a clear boundary between the outside and inside of your network. Firewall solution provides filtering, ensuring that the users inside your network can access the external services easily. It also prevents your internal computers from getting the connection from external computers until they meet specific access requirements.
Key Uses of Firewalls
- Firewalls can be used in corporate as well as consumer settings.
- Firewalls can incorporate a security information and event management strategy (SIEM) into cybersecurity devices concerning modern organizations and are installed at the network perimeter of organizations to guard against external threats as well as insider threats.
- Firewalls can perform logging and audit functions by identifying patterns and improving rules by updating them to defend the immediate threats.
- Firewalls can be used for a home network, Digital Subscriber Line (DSL), or cable modem having static IP addresses. Firewalls can easily filter traffic and can signal the user about intrusions.
- They are also used for antivirus applications.
- When vendors discover new threats or patches, the firewalls update the rule sets to resolve the vendor issues.
- In-home devices, we can set the restrictions using Hardware/firmware firewalls.
Security features of the firewall
- A hardware firewall is used to detect suspicious traffic.
- Using the hardware firewall, the data packets, which seem suspicious, can be blocked.
- Using the analyze content of the NGFW firewall, the leakage of data can be detected.
- A firewall provides a secure network so that multiple persons can interact, for example, online video games.
- A firewall is used to protect your private information like online banking credentials, social security numbers.
How Does a Firewall Work?
As mentioned previously, firewalls filter the network traffic within a private network. It analyses which traffic should be allowed or restricted based on a set of rules. Think of the firewall like a gatekeeper at your computer’s entry point which only allows trusted sources, or IP addresses, to enter your network.
Only incoming traffic that has been set up to be accepted by the firewall is accepted. Based on previously set security criteria, it distinguishes between legitimate and malicious communication and either permits or bans particular data packets.
These rules are based on several aspects indicated by the packet data, like their source, destination, content, and so on. They block traffic coming from suspicious sources to prevent cyberattacks.
For example, the image depicted below shows how a firewall allows good traffic to pass to the user’s private network.
Fig: Firewall allowing Good Traffic
However, in the example below, the firewall blocks malicious traffic from entering the private network, thereby protecting the user’s network from being susceptible to a cyberattack.
Fig: Firewall blocking Bad Traffic
This way, a firewall carries out quick assessments to detect malware and other suspicious activities.
There are different types of firewalls to read data packets at different network levels. Now, you will move on to the next section of this tutorial and understand the different types of firewalls.