Network Firewall: Definition
A network firewall shields a computer network from unauthorized access. It could take the form of a software program, a hardware device, or a combination of the two.
Network firewalls are responsible for protecting an internal computer network against malicious access from the outside, such as vulnerable open network ports or malware-infested websites. Network firewalls can be found in schools, businesses, intranets, and homes. It is also possible to configure a network firewall to limit the access of internal users to outside connections, for instance, in the case of workplace locks or parental controls.
Forms of Network Firewalls
Network administrators are provided with a wide range of approaches when choosing and configuring protection for the networks they oversee. The different types of firewalls include:
- Next-generation firewall (NGFW): Employs a multilayered approach to integrate enterprise firewall capabilities with an intrusion prevention system (IPS) and application control.
- Packet-filtering firewall: Studies packets in isolation and does not know the packet’s context.
- Firewall: Checks packets at the application layer of the Open Systems Interconnection (OSI) reference model.
- Inspection firewall: Studies network traffic to determine whether one packet is related to another packet.
Network Firewalls vs. Computer Firewalls
It is possible for you to install a few software firewall programs directly onto the hard drive of a computer that needs it. Some antivirus programs are also available with inbuilt firewalls. In the case of a network firewall, you will be able to disable a computer-based firewall. However, these firewalls protect only the computers that run them. In contrast, network firewalls are capable of protecting the whole network and are usually installed at the network gateway.
How a Firewall Works
When your computer is equipped with firewall protection, every single thing that goes in and out of it is monitored. The firewall has the potential to monitor all this information traffic in order to allow ‘good data’ in and block ‘bad data’ from entering your system.
A firewall differs from a simple traffic analyzer, however, in that a network administrator can actually take action to control that traffic. A few firewalls can even be employed for blocking everything except users and actions that are specifically allowed by you. This granular approach allows you to block all activity on a network so that you will be able to manually set up safeguards against network-related threats.
- Proxy service: A firewall proxy server is an application that functions as an intermediary between systems. Information from the internet is saved by the firewall and then transmitted to the requesting system and vice versa. Firewall proxy servers are capable of operating at the application layer of the firewall, where both ends of a connection are made to conduct the session via the proxy. They work by developing and running a process on the firewall that mirrors a service as if it were actually running on the end host, thus consolidating all data transfer for a specific activity to the firewall for scanning.
- Stateful inspection: This is considered to be a modern method of firewall scanning, that does not depend on the memory-intensive examination of all information packets. A ‘stateful’ firewall holds vital attributes of each connection in a database of reliable information, for the duration of the session. These attributes, together known as the ‘state’ of the connection, could include details like the IP addresses and ports involved in the connection and the sequence numbers of the packets that get transferred. The firewall compares data being transferred to the copy applicable to that transfer held in the database. The information is allowed only if the comparison yields a positive match otherwise it is denied.
- Packet filtering: This is the most elementary form of firewall software that employs pre-determined security rules to develop filters – if an incoming packet of information gets flagged by the filters, it is not allowed through. Packets that succeed in making it through the filters are sent to the requesting system whereas the others are rejected.
Firewall Security
The constant increase in cybercrime continues to become a threat to businesses all over the world. You are indeed completely aware of the fact that your organization needs firewall security and you may already have a firewall management program in place. However, it is always essential to have adequate knowledge about what exactly is firewall security and what are the benefits provided by effective firewall security software.
Originally, the word firewall literally referred to a wall, which was built to stop the spread of a fire. In the field of computer firewall protection, a firewall is actually a network device that has the potential to block specific types of network traffic, developing a barrier between an untrusted network and a trusted network. It is similar to a physical firewall referring to the fact that firewall security tries to block the spread of computer attacks.
Firewall security is important as it has the following benefits:
- Blocks unwanted content
- Prevents ransomware from gaining traction
- Protects your computer from unauthorized access
- Helps keep your private data such as social security number or online banking credentials safe
- Develops a secure network for multi-person interaction, such as online video games