Firewall types are very important to know, after more than 30 years, network firewall technology remains a vital component of a business’s network security arsenal. The firewall has shown to be an excellent technology for blocking harmful network traffic. As with any key technology, developments have broadened the firewall’s capabilities and deployment possibilities.
In the early days of the modern internet, when system administrators found that external attackers were breaching the perimeter defenses of networks, they created the firewall. Unavoidably, there would be a procedure in place to monitor network data for apparent indicators of accidents.
How Do the Different Types of Firewalls Function?
Typically, firewalls are put inline across a network connection to monitor all traffic traveling through that point. They must differentiate between attack packets and innocuous network protocol traffic as they travel.
Firewalls monitor traffic and compare it to predefined rules to filter out potentially malicious stuff. Even though no security solution can entirely forecast every data piece’s aim. Advancements in security technology enable the utilization of patterns in network data that have previously signaled assaults on other firms.
Every firewall has rules that outline the conditions under which a specific packet (or group of packets in a transaction) can be routed to its intended recipient safely.
The five types of firewalls that are still indispensable in contemporary business contexts are listed below.
1. Packet Filtering Firewall
Firewalls that filter packets operate inline at network intersections where routers and switches function. These firewalls don’t send packets where they need to go. Instead, they compare each one to a list of standards that have already been set. Such as the allowed IP addresses, packet type, port number, and other information from the protocol headers of packets. Complex packets are typically discarded without ceremony, meaning they are not transmitted and eventually disappear.
Pros
- One device is capable of filtering the entire network.
- incredibly rapid and cost-effective at scanning traffic
- Other network resources, user experience, and network speed are unaffected.
Cons
- Packet filtering lacks the broader context on which other types of firewalls rely because it focuses exclusively on IP address or port information.
- lacks payload validation and is readily manipulated
- Not often are networked the best solution.
- It might be challenging to create and administer access control lists.
Even though packet filtering is a low-cost firewall, it may not always provide the appropriate level of security for all use cases. Packet filtering provides a fundamental level of security that protects against known risks for small or restricted businesses.
Larger firms can add a layer of protection by employing packet filtering to sift through internal departmental communication for potentially dangerous content.
2. Circuit-Level Gateway
TCP handshakes and other network protocol session initiation messages are checked to ensure the session is legitimate, and the distant system is trusted.
It is another straightforward approach for detecting malware. However, they do not inspect the packets.
Pros
- Block all other communications, and only requests for transactions are processed.
- Simple to install and employ
- Low-priced with minimal influence on customer experience
Cons
- If not utilized with other security solutions, circuit-level gateways offer no protection against data leakage from devices inside the firewall.
- There is no monitoring of the application layer.
- Changing the regulations is necessary to keep them relevant.
Even though packet filtering firewalls are less secure than circuit-level gateways, they should still be in conjunction with other systems. Combine circuit-level gateways with application-level gates, for instance. This approach combines the benefits of packet-level and circuit-level gateway firewalls with content filtering.
3. Application-level Gateway
This device, which is technically a proxy but also known as a proxy firewall, serves as the network’s sole point of entry and exit. Application-level gateways filter packets depending on various criteria, including the HTTP request text and the target port, which indicates the service for which the packets are meant.
Although application-layer gateways provide substantial data security, they can severely impede network performance and are complex to administer.
Pros
- Before permitting traffic to flow through the proxy, examines all communications between external sources and devices within the firewall, analyzing the address, port, and TCP header information and the actual content.
- Allows access to a website but restricts which pages a user can view.
- Ensures user privacy
- Negative aspects of application-level gateways
- Can reduce network efficiency
- Costlier than some alternate firewall options
Cons
- Support, not every possible network protocol.
- Application-layer firewalls offer the best protection against attacks on online applications. They can restrict access to harmful websites and prevent the firewall from leaking sensitive data. However, they may cause a communication delay.
- A state-of-the-art inspection firewall
In addition to evaluating each packet, state-aware devices detect if a packet is part of a current TCP session or another network session. Although this provides a higher level of security than circuit monitoring or packet filtering alone, it has a more significant negative impact on network performance.
The multilayer inspection firewall is a version of stateful inspection that considers the flow of transactions across multiple protocol layers of the seven-layer Open Systems Interconnection (OSI) architecture.
Stateful Inspection Firewall
In addition to evaluating each packet, state-aware devices detect if a packet is part of a current TCP session or another network session. Although this provides a higher level of security than circuit monitoring or packet filtering alone, it has a more significant negative impact on network performance.
The multilayer inspection firewall is a version of stateful inspection that considers the flow of transactions across multiple protocol layers of the seven-layer Open Systems Interconnection (OSI) architecture.
Pros
- To provide a higher level of security, the connection status of IP addresses, payloads, and examine the entire session.
- Offers extensive user control over the network’s acceptance or rejection of content
- Numerous ports for incoming and outgoing traffic are unnecessary.
- Provides efficient logging capabilities
Cons
- It uses a lot of resources and impedes network connectivity.
- Costlier than competing firewall options
- It does not provide authentication tools to verify the legitimacy of traffic sources.
Most organizations benefit from the use of a stateful inspection firewall. These devices serve as a more thorough gateway between computers and other assets within the firewall and resources beyond the enterprise. They also can be highly effective in defending network devices against particular attacks, such as DoS.
5. Next-Generation Firewall
A typical network security appliance (NGFW) combines packet inspection and stateful inspection with some deep packet inspection (DPI) and other network security technologies such as an intrusion detection/prevention system (IDS/IPS), malware filtering, and antivirus.
DPI checks the actual data included within a packet, whereas classical firewalls merely inspect the protocol header. A DPI firewall can identify if the payload of a packet paired with additional packets in an HTTP server’s response forms a legitimate HTML-formatted response.
Pros
- It delivers the most significant level of filtering by combining DPI with malware filtering and other restrictions.
- It follows all traffic from Layer 2 to the application layer to provide more exact insights than other methods.
- To give appropriate context, automatic updates are possible.
Cons
- Organizations must integrate Next-Generation Firewalls (NGFWs) with other security solutions, which can be challenging.
- Expensive compared to other types of firewall
NGFWs are a regulates essential safety net for organizations in industries like healthcare and finance. These firewalls’ multipurpose capabilities appeal to persons who have a thorough awareness of the threat landscape.
NGFWs produce the best results when integrated with other security systems, typically requiring a high level of expertise.
Delivering Through a Firewall
Options for security implementation have expanded in step with IT consumption paradigms. Now, install firewalls as software, hardware, or service.
Firewalls Based on Hardware
A hardware-based firewall solution is a safe gateway for internal and external network devices. Because hardware-based firewalls are standalone appliances, they do not drain processor power or other host device resources.
These devices, often known as network-based firewalls, are appropriate for medium- and large-sized enterprises with various devices to secure. Configuring and maintaining hardware-based firewalls requires more technical knowledge than host-based firewalls.
Firewalls That Run on Software
A host firewall is a software-based firewall run on a server or another piece of computer hardware. Install host-based firewall software on every device that needs security. Software-based firewalls use some of the CPU and RAM of the device they are running on.
Software-based firewalls provide exceptional virus and other hazardous content protection for individual devices. They can differentiate between the programs operating on each host and filter incoming and outgoing traffic. With such granular control, it is feasible to enable communications to/from one program while prohibiting communications to/from another.
Cloud/hosted Firewalls
Managed security service providers offer firewalls in the cloud (MSSPs). Configure this hosted service to monitor both internal and external on-demand network traffic. MSSPs may maintain cloud-based firewalls, also termed firewalls as a service, making them perfect for large or geographically distributed enterprises with security resource gaps. Cloud-based firewalls can also benefit smaller firms with less personnel and expertise resources.
Conclusion
When choosing the proper firewall, it is vital to consider what the firewall is protecting, the organization’s financial resources, and the infrastructure’s design. One company’s ideal firewall may not be suitable for another.
If you need a firewall to protect your business, contact ICT Distribution; they will provide the best service available.