Firewall

Should You Build or Buy a Firewall for Your Web Server Farm?

When it comes to securing your web server farm, one of the most critical decisions you’ll face is whether to build your own firewall or purchase a dedicated device. This decision can have a significant impact on your traffic management, security, and overall system performance. In this blog post, we’ll dissect the advantages and disadvantages of both options to help you make an informed choice, considering your specific requirements.

Understanding Your Requirements

In your case, you have a Linux web server farm consisting of five web servers handling approximately 20Mbps of web traffic. Your requirements for the firewall are as follows:

  • Dynamically block rogue traffic
  • Dynamically rate limit traffic
  • Block all ports except 80 (HTTP) and 443 (HTTPS)
  • Limit access to port 22 (SSH) to a specific set of IPs
  • High availability setup

These requirements underline the importance of a resilient and flexible firewall solution. Let’s explore your options: building versus buying.

Building Your Own Firewall

Pros:

  • Customization: When you build your own firewall using a system like Linux or *BSD, you can tailor it to meet your specific needs. This means that you can implement dynamic traffic control through scripts in languages like shell, Python, or Perl.
  • Cost-Effective: Building your own firewall may save you costs associated with purchasing specialized hardware.
  • Scalability: You can scale your system as needed without relying on a vendor’s specifications.

Cons:

  • Traffic Handling Limitations: While you could achieve data rates in the 300Mbit/sec range, you might hit PCI bus limitations when handling larger traffic volumes. This means you’ll need to carefully evaluate whether your expected load will exceed this capability.
  • Maintenance Challenges: Building a solution means you’re responsible for ongoing maintenance, updates, and troubleshooting.

Performance Potential:

If you’re contemplating the build route, consider that the performance of your self-built firewall will largely depend on your hardware. Regular assessments will help determine if your system can handle your network traffic effectively.

Buying a Dedicated Firewall

Pros:

  • Simplicity: Purchasing a dedicated firewall device can simplify the setup process. These devices often come pre-configured and require less time to implement.
  • Optimized Performance: Dedicated firewalls are usually optimized for traffic handling and can provide robust performance without the potential hardware limitations of a DIY solution.
  • Vendor Support: You will typically have access to vendor support, making it easier to troubleshoot problems or expand capabilities.

Cons:

  • Cost: Buying a dedicated device can require a significant upfront investment, which may not align with your budget.
  • Limited Customization: Depending on the device, making dynamic changes to manage traffic may be more complex compared to a custom-built solution.
  • Potential Traffic Issues: Some dedicated devices may face the same traffic limitations as conventional PCs, necessitating careful review of the manufacturer’s specifications.

Final Considerations

Ultimately, the decision to build or buy a firewall should be based on your specific needs, budget constraints, and your team’s technical expertise. For instance, as an example from experience, dual FreeBSD firewalls have effectively managed over 40Mbit/sec of traffic with minimal load in a professional environment.

Taking into account your traffic requirements and the technical challenges of your current setup, weigh the pros and cons carefully. Whether you lean towards a custom solution or a dedicated device, ensure that your choice can scale with your future needs.

By considering all aspects involved in this critical decision, you will be better prepared to select the firewall solution that best enhances the performance and security of your web server farm.