OPNsense® Firewall/Router/VPN/IDPS

I use OPNsense  for my small network and operate a practical lab with seven to eight computers. For the organizations where I provide tech support, they fully depend on OPNsense .

I find everything valuable in OPNsense. The configuration and reporting aspects are what we require. Reporting  on user access and data consumed is fascinating in OPNsense, and the configuration offers a clear idea of everything that I have configured in DHCP.

The key metrics I track to measure the effectiveness of reporting tools include the graphic interface and real-time statistics, which are much better in OPNsense compared to SonicWall. If I want to export something, that is easy from OPNsense. Using blacklist and whitelist for creating policies, such as port forwarding, is very straightforward. In OPNsense, everything can be done on a single screen: identifying the source of packets, determining what to do with them, and deciding where they should land is the most convenient aspect. Additionally, grouping IP addresses in OPNsense is very easy, making the overall experience very user-friendly.

I assess OPNsense's intrusion detection capabilities through practical testing. When it comes to the LAN, if I unplug the cable, it displays a message indicating the disconnection. This helps me identify that this is the onboard LAN card and this is the PCI Express LAN card, and I note it down for future reference in documentation to assist the next person.

I find the load balancing features quite satisfactory as I am using two WANs with this system. The load balancing features have no negative impact on my operations, and I am satisfied with this aspect as it automatically takes over the network, directing load to the second WAN if one fails.

I have attempted to configure OPNsense VPN features, but I was not successful due to time constraints. However, I believe that with some effort, the VPN will work fine. I was using OpenVPN  simultaneously for computer-to-computer communication, but not with OPNsense, though I am confident it will fulfill my needs. I want to implement a site-to-site VPN, but that project was dropped in between.

I want to mention that the proxy is mandatory in OPNsense if you want to use the antivirus plugin. Without a proxy, you cannot use the ClamAV antivirus plugin. I think that should be modified, as it should work without configuring a proxy. This is the only aspect in which OPNsense is falling behind because implementing a proxy requires system-to-system attention. Alternatively, using a transparent proxy poses a threat if not properly configured.

In OPNsense, I would appreciate an improvement in the proxy requirement. I need it to skip the proxy for implementing antivirus. I have some personnel who visit outside the premises, and if I statically configure the proxy on their laptops, they cannot connect when they join another network. My suggestion is to consider this improvement.

I have been working with OPNsense for around five years.

I did not experience too many problems with the implementation or configuration of OPNsense in my system. The main thing to note is that OPNsense is based on BSD, so in some cases, changing the machine causes references of the LAN card to change. For instance, on a single machine, it might show en0, en1, while on a different machine, it shows enp0, enp1. This inconsistent naming convention can be confusing during configuration, especially regarding which port is which.

OPNsense is completely scalable for my needs.

Before OPNsense, I introduced SonicWall a couple of months ago. I worked with the TZ series, specifically the TZ 270 model.

We work on the technological side of things, systems, automation systems. When it comes to Layer 2, 3, 4, we hit firewalls. We work with a big company in the United States, so we usually use their recommended ones. There is a certain flexibility for products. We are not bound to buy a certain product, so it is flexible.

This is not robotics; that is process automation. It involves DCSs, PLCs, that type of systems.

DCS refers to control systems and PLCs (Programmable Logic Controllers). It is basically automation for processes such as refineries, chemical factories, paper mills, so that is what we do.

We have been using OPNsense  in a lab, so we are actually experimenting with it.

YouTube is one of the best features with OPNsense .

In today's world, it is YouTube that stands out. It is just a big game, with someone writing code, putting it in a box, an embedded system and writing the 200-page manual on how to use it. In my opinion, down the road it is plain old TCP/IP, UDP in terms of communications and it is completely overrated. But this is what we have to live with unfortunately, that is what is out there. YouTube provides video explanations, and that brings you to speed, instead of sitting down and reading a 200-page document on the product.

I do not appreciate the pricing or the licensing of this product.

It is more expensive than it should be for what it does. Consider the commercial products - OPNsense offers community editions which are free, and then you have to determine the difference between a licensed version and community version. You have to pay for features. I understand people provide something and you have to pay for that service. But pricing in my opinion is just too expensive. It makes no sense. It moves in the direction of a monopoly. It implies that you depend on that system and have no choice but to spend. With firewalls there is competition. When it comes to operating systems, that is harder. Look at Microsoft - they have a monopoly more or less, so there is almost no alternative.

I have not had that chance yet with OPNsense, but this might be a good point. This is a differentiator. It is not just OPNsense firewalls, it is any other gizmo provider out there. You have Dell, you have Microsoft. Try to get support. The first question they ask you is about your support contract. If you say you do not have one, it is finished. This is where the monopoly starts. I am not sure how it is with OPNsense. If you call for support, it would be a test, actually. I have not done that yet. They might let you hang, saying you need a support contract, and finish. I do not know.

I do not think there is a difference. All these products that are out there are more or less on the same level when it comes to setting up OPNsense initially.

We would have to do testing with OPNsense in an environment doing pen tests using cybersecurity tools that are available to pen test and see what happens. Because I am not in the IT group, and this is not our focus anyway, we have not done this bench testing, benchmarking, firewalls, or whatsoever, on-premises or not, all versions, hardware related, software firewalls.

With OPNsense, I find that you have to actually worry about this. There are two opinions on this. If I were an IT person, I would say it is fine, but I am not. I am an engineer. When I look at this IT stuff, in my opinion, this is in today's world completely overrated for what it is supposed to do. The fact that it is public makes it just not safe. And the rest is just a game. Firewall A, B, C, D, E, F, G, standard 1, 2, 3, 4, 5, 6, 7, 8. It will never be safe as long as it is public.

You want a game changer, you have to make the networks private. And this has to run not through your little company, it has to run through the ISP. It is the internet community that has to handle this. I cannot predict it, but this public stuff over there is public. In the end, whatever is public-facing is not safe. I make sure I have backups in place. When something crashes, I restore as quick as I can.

I do not use OPNsense VPN features.

As a company, this is a big game that is being played. I do not appreciate this because I am actually a chemical engineer and I want to focus my energy on how to make products with better quality, more efficient, using less energy, less raw materials, and so forth. Here  you are stuck with running a game just to get simple communications up safely because it is on the public internet, which makes absolutely no sense. Instead of being a boon for remoting and productivity enhancement, I think we have reached the point where it is the opposite.

There are many ways down the road I see that will happen, probably some private type of networks that businesses get from the ISPs, private connectivity, so that you can clearly separate what is public and what is not. All you see happening and this patching up is IP version 4, NATting, PATting, it makes no sense. We try to keep things isolated as much as we can. Whenever it comes to a business-related solution, we will always go with a provider. We are actually outsourcing it; we are not doing it ourselves.

My rating for OPNsense is 5 out of 10.

I work with OPNsense  to create my capstone project in the sixth semester. I work with OPNsense  for my capstone project, and I am now planning to make it my main firewall in my network at home, and I'm planning to use it also in case I work in the company.

For my capstone, I use OPNsense for my project and its broader benefits for enterprise and cybersecurity context. OPNsense is an open source based firewall and routing platform. It offers enterprise-grade features such as intrusion detection and prevention system, VPN support, traffic shaping, and web filtering, all without license cost. This platform has a modular design, a clean web-based GUI, and frequent updates that prioritize security and usability. It competes with commercial firewalls such as Cisco ASA , FortiGate , and Palo Alto, but stands out because it's community-driven, cost-effective, and transparent.

I find OPNsense's feature of acting as a central firewall and gateway most valuable, providing robust point segmentation between the internal network and DMZs in my capstone project, intrusion detection to monitor malicious traffic, VPN services for secure remote access, and logging and monitoring for compliance and auditing. This allows me to simulate a real-world enterprise environment on a smaller scale, demonstrating both security hardening and network efficiency.

OPNsense impacts my projects and home network positively because its cost-effectiveness is perfect for lab and enterprise setup without expensive licensing. The flexibility, easy VLAN and DMZ configuration supports different zones such as web servers, mail servers, and log servers. The security-first design for IDS/IPS integration helps me showcase modern defense-in-depth strategies. The user-friendly management through the web GUI makes it possible to manage complex firewall rules clearly, which is critical when documenting and presenting a capstone. Scalability is also an advantage. Although my project is lab-based, OPNsense can scale into production deployments in SMBs and enterprise.

The documentation should be clearer because I faced some difficulties navigating many options. Providing clearer documentation will be helpful for other students who are new to experiences with OPNsense.

I have been using OPNsense throughout my capstone project in the sixth semester.

OPNsense is stable in my experience and has been reliable for my projects and home network. For my capstone project, OPNsense consistently performs as expected, maintaining stable routing and firewall rules across multiple VLANs and DMZs. The IDS/IPS engine using Suricata detects test intrusion attempts without causing noticeable performance degradation, and VPN tunneling works reliably, allowing secure remote access to my simulated enterprise work. Logs and monitoring tools provide clear visibility, which is important for documenting my project. For home and small network use, OPNsense is also reliable, providing enterprise-grade security at no cost, which is valuable for students and professionals building labs. It has a user-friendly GUI that makes managing the firewall straightforward, and the community support is active, making troubleshooting and updating reliable.

OPNsense is scalable, but the degree of scalability depends on the hardware resources and the network design. In theory, OPNsense can handle small home networks and even large enterprise environments if deployed on sufficiently powerful hardware or virtualized on a clustered system. It supports features such as high availability pairs, load balancing, and multi-WAN setups that allow it to scale beyond a single device. In practice, for my capstone project, I didn't simulate a very large enterprise, but I did segment multiple VLANs, set up DMZs, and enable IDS/IPS, and OPNsense managed this well without performance issues. This showed me that it can handle at least mid-sized network complexity reliably. I haven't tested it for large production environments, but it is a reliable, cost-effective, and scalable solution for labs and mid-sized enterprises.

In my personal experience, I mostly interact with the community side and find it responsive and well documented. The forums answer most configuration issues I face, and the documentation is up to date. Compared to some open-source projects with weak support, OPNsense stands out for having both a strong community and commercial backing options.

I selected OPNsense as a primary solution in my project because of its strong open-source community support, robust features, and suitability for a cost-effective lab environment. If I were to switch to another solution, the most likely candidate would be pfSense or a commercial firewall appliance such as Cisco ASA  or FortiGate .

For pfSense, built on a similar FreeBSD foundation with a long-standing reputation in academic and enterprise labs, I might choose it if I need certain community plugins or enterprise-level add-ons that are more mature in pfSense. The reason I initially didn't switch away from OPNsense is that it provides everything required for my capstone: VLANs, DMZ segmentation, IDS/IPS integration, VPN functionality, logging and monitoring, strong documentation, and GUI management. But for a production environment, I might recommend switching to Cisco or FortiGate for scalability in a very large network to ensure professional support in case of critical downtime and integration with another enterprise security system.

Before choosing OPNsense, I evaluated other options to ensure the choice aligns with both the technical goals of my project and real-world industry practice. The main alternative I considered was pfSense, which is very close to OPNsense. Both are free-based. I considered it because it's widely used in academic labs and has a strong plugin ecosystem. Ultimately, I preferred OPNsense for its more modern user interface, frequent updates, and strong focus on security features.

Regarding the pricing, OPNsense has no cost. The setup is somewhat easy, and for licensing, I haven't tried the paid version yet, but overall it's perfect. I save time while working on my capstone project because OPNsense helps me save time during setup and configuration, especially for the intrusion prevention system that helps me be more aware of monitoring and catching any malicious packets or traffic already passing through my network.

The GUI-based OPNsense is very useful and easy to deal with because many people find it frustrating to deal with command line projects. OPNsense provides a web-based GUI that makes the matter easier and more efficient to look at and to deal with.

I will discuss the general benefits of OPNsense, which include compliance support that is useful for organizations pursuing ISO 27001 and PCI DSS, as it helps enforce security controls. One benefit is open-source transparency; unlike black-box firewalls, its code is reviewable and trusted by the community. Rapid innovation through frequent updates means it stays aligned with modern threats, and many organizations use OPNsense as a cost-effective alternative to commercial appliances without sacrificing core security capabilities.

From using OPNsense, I think it could be easier, and I will talk about the lessons I learned. I gained hands-on experience with firewall rules design and the challenges of balancing security with usability. I learned the importance of logging and monitoring for incident response. Furthermore, I realized that open-source tools such as OPNsense can be viable for both learning and professional deployment. Most importantly, OPNsense helped me connect academic theory with practical enterprise-grade solutions.

I rate OPNsense a nine because the documentation needs more clarification.

If I were advising others considering OPNsense, I recommend a few key points. Start with clear goals; OPNsense has a wide feature set including firewalling, IDS/IPS, VPNs, traffic shaping, and more. Define what you need first—segmentation, remote access, monitoring—so you don't get overwhelmed. Invest in proper hardware since performance and scalability depend heavily on CPUs, RAM, and network interfaces, especially for IDS/IPS. Choose hardware with enough power; otherwise, packet inspection can slow the network. Leverage the community by utilizing the forums, GitHub , and documentation, which are excellent. Most configuration challenges I face have already been solved by others. Keep it updated because OPNsense has frequent updates and security patches. Staying current ensures you are protected against new vulnerabilities. For labs and mid-sized enterprises, open source is a fantastic solution; it is cost-effective, feature-rich, and transparent. For very large enterprises that require vendor SLAs or guaranteed throughput, you may want to evaluate commercial appliances alongside OPNsense.

My main use case for OPNsense  is as a firewall on-premises.

Using OPNsense  in my work environment, it serves as the first line of defense. I'm using it for filtering, using my own repository and Dnsmasq to filter unwanted websites. I'm using it as an SD-WAN, as an IPS, intrusion prevention software, and as a next-gen firewall.

As the first line of defense of my network, OPNsense firewall acts effectively, helping me reduce the number of attacks that my network suffers or has been impacted by a huge percentage. Due to its openness and because it's free, and it's a next-gen firewall, it can go up to the application layer to protect my network, which is very good and unique compared to traditional firewalls.

OPNsense is deployed on-premises in my organization.

In my opinion, the best features OPNsense offers are that it's open source, so it can be implemented in whatever scope or environment that I need. I just need to scale the hardware for that environment and I don't have to pay a license, perpetual or renewal.

The open-source aspect and flexibility of OPNsense have helped me significantly, especially due to the difference in the currency exchange rate here in Egypt, where the licensing and budgeting for IT infrastructure is very hard right now due to the high cost of the products in the Egyptian currency. Most companies see that the IT department is a consuming department, not one that's bringing money, with the ROI being an improvement in SLAs in a few percentages. We have a tight budget in Egyptian pounds, so when we get stuck because the budget has ended, we have to prefer open-source solutions to save budget, and here the open source can rise and shine. I don't need the license, so I will save cost in my budget that I can use in another product that doesn't have any alternative.

People sometimes overlook that OPNsense is modular, and that you can install plugins to improve it. You don't have to use it bare-metal OPNsense releases; it's modular, and you can add whatever plugin or features that you need to be added.

OPNsense can be improved by making it more user-friendly, as its current UI is not that user-friendly when compared to paid software such as Sophos. Sophos has a free version that is very limited, but OPNsense could be fantastic if this point is addressed correctly.

I have been using OPNsense for a couple of years.

OPNsense is stable.

OPNsense's scalability is excellent; I just need to resize my hardware and upgrade the server, and voilà, I am good to go.

OPNsense is open source, so you have to rely on the community for customer support.

I previously used Sophos Home , but I switched because it's very limited.

My experience with pricing, setup cost, and licensing for OPNsense has been very positive since it is open source, reducing the cost of licensing. I don't need to license the software as it's free, and I can also scale the hardware, which cost me around 30,000 Egyptian pounds, less than a thousand dollars for used servers. This initial cost just required purchasing the server and installing the open-source software, reducing the amount of money needed for an enterprise firewall.

I have seen a return on investment as I saved a chunk of money, nearly $100,000, needed for licensing for an enterprise firewall such as FortiGate  or Sophos.

We saved up to half a million Egyptian pounds, which is nearly $100,000 yearly on licensing or subscription using this kind of software. This saved a huge amount of money, and the network attacks reduced by approximately 60% after using that, even without customizing the custom configuration yet. Currently, I'm working on custom configuration.

Before choosing OPNsense, I evaluated pfSense, but pfSense is maintained by Netgate, which has filed for bankruptcy, so it's considered legacy and not fit for the modern network. OPNsense is a good option.

I rate OPNsense 8 out of 10. It is a straightforward product that has nothing crazy to do with it.

My advice for others looking into using OPNsense is to get creative.

My company does not have a business relationship with this vendor, as we are just customers.