Network firewalls provide an essential layer of security to your enterprise. It acts as a barrier to the outside network and protects the internal network from unwanted and unauthorized activities. A firewall provides a security solution to the devices connected to the enterprise server. These devices can be hardware or software in nature.
The main aim of the network firewall is to protect the enterprise network from incoming outside networks. There are two networks available in the organization; the inner and outer network. The internal network is created at the enterprise level, and the external network is the network that is out of the internal network. Here we will study the different types of firewalls in detail.
According to Norton, “A firewall is a security device in the form of computer hardware or software. It can help protect your network by acting as an intermediary between your internal network and outside traffic. It monitors attempts to gain access to your operating system and blocks unwanted incoming traffic and unrecognized sources”.
A firewall only allows authenticated traffic to enter a private enterprise network. A firewall can be hardware, software, or a combination of both and work as the first line of defense against malicious attacks. A physical or hardware firewall allow only authenticated networks to enter the private network.
According to Wikipedia, “In computing, a firewall is a network security system that monitors and controls the incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted network and an untrusted network, such as the Internet. The term firewall originally referred to a wall intended to confine a fire within a line of adjacent buildings. Later uses refer to similar structures, such as the metal sheet separating the engine compartment of a vehicle or aircraft from the passenger compartment. The term was applied in the late 1980s to network technology.”
As a security solution for enterprise networks, the firewall checks all the incoming and outgoing addresses before entering the private network. After reviewing the details, the outside network can join the internal network. The inner software firewall scans that network and can allow or block based on the rules. Firewalls only allow traffic from trusted IPs to protect the enterprise network from malicious activities.
There are two types of firewalls: hardware and software firewall. Both the firewalls are controlled remotely and with the help of software. The installation of software firewalls is built on individual products or devices. It helps prevent the access of various applications and blocks outsider networks to protect the internal networks from malicious attacks.
A software firewall is expensive as it uses the (CPU) central processing unit and RAM (Random access memory) of the devices on which they are installed. Managers need to manage and configure them individually.
Hardware firewalls are physical devices having all the computing resources. They act as barriers between internal networks and the outside Internet. They control the data traffic from unauthorized networks and restrict them from entering the enterprise network. A hardware firewall is the best security solution for the enterprise with many devices on the same web as it will block the viruses before they reach any endpoints.
In the computing, the firewall has a total of five types:
- Packet filtering firewall
- Circuit-level gateway
- Stateful inspection firewall
- Application-level gateway (proxy firewall)
- Next-generation firewall (NGFW)
The structure of a packet filtering firewall is simple. It is the most basic and the oldest firewall in computing. These firewall uses to check the data traffic for its source and destination IPs. These firewalls also help prevent unwanted and unauthorized networks from the source port, destination port, and protocols. Packet filtering firewalls are used to monitor every packet independently without knowing its previous record of established connections. Hence, this makes firewalls limited in their performing capacity against viruses.
Circuit-level gateway is somehow similar to a packet filtering firewall. Like the packet filtering firewall, with very few resources, they perform the single check activity. While working at the session layer verifies TCP (Transmission Connection Protocol) to keep track of active sessions. Moreover, the main goal of this firewall is to determine the security of established connections.
Circuit-level gateways are simple, cost-effective, and can impact network performance. However, they provide incomplete security solutions as they cannot inspect the content of the data packets. Therefore, malware inside the data packets can easily bypass the circuit-level gateway, and hence, another type of firewall is configured.
Stateful inspection firewalls have some extra features than circuit-level gateways. They keep track of established connections and perform data packet inspection to deliver security. Stateful inspection firewalls work on destination and source IPs by creating a state table. Instead, they make their own directives to allow entering traffic depending on a hardcoded set of rules based on the information.
Application-level gateways or Proxy firewalls are connected to the application layer with a proxy device. It helps to detect the malicious network coming from outside before entering the enterprise network. Moreover, if the client wants to join the network, he must send a request. Hence, the request is then passed through the proxy firewall. And if the bid gets verified, it forwards to one of the internal devices.
Next-Generation Firewall (NGFW) offers additional security features to overcome the limitations. Traditional firewalls have some restrictions and cannot provide complete security to data packets; hence, to overcome this, the next-generation firewalls come into the picture. Therefore, it is the single solution for many security issues. Therefore, with NGFW, the security performance won’t affect and deliver the best service.
According to Gartner, “Next-generation firewalls (NGFWs) are deep-packet inspection firewalls that move beyond port/protocol inspection and blocking to add application-level inspection, intrusion prevention, and bringing intelligence from outside the firewall. An NGFW should not be confused with a stand-alone network intrusion prevention system (IPS), which includes a commodity or non-enterprise firewall, or a firewall and IPS in the same appliance that is not closely integrated”.
Another essential feature of the next-generation firewall is a deep inspection to detect viruses and malware. Further, the feature for intelligent traffic and different resource analysis technique helps to do the inspection. Hence, the attacks such as DDoS are blocked with the help of NGFW.
The application for NGFW firewalls is best suitable for companies who want more security options in a single solution. Therefore, businesses need to spend more money on such firewalls, and the administration needs to configure them with other security systems.
Every organization needs the best security solutions for its private network. But it is impossible to get a single key with a one-size-fits-all that can fulfill all the security requirements. Different types of firewalls have some benefits and some limitations. For instant, a Packet filtering firewall has limited security, and it is a simple type of firewall. Therefore, application-level gateway and stateful-level gateway firewalls can compromise the security performance.
But the next-generation firewall (NGFW) is a complete package of all the solutions. The security performance is very good, but this needs a high budget. Moreover, companies with a big budget for network security can use a next-generation firewall.
As the number of attackers increases daily, organizations need to improve their security levels. A single firewall cannot manage all the security performance issues and may lead to network damage. Hence, a single firewall is not enough to protect your organization’s internal network.
In conclusion, among all the types of firewalls, the next-generation firewall is the set of many security solutions. It combines multiple features of other firewalls and provides the best network performance. It offers a broader and deeper security solution for businesses that needs the best various security solutions for their private network.