What Is DNS Filtering?

DNS filtering is a technique used to control access to websites and online content by filtering DNS queries based on predefined criteria. Essentially, it acts as a gatekeeper between your device and the internet, blocking or allowing access to specific websites or categories of websites.

How DNS Filtering Works

DNS filtering controls website access by managing DNS requests. When a user tries to visit a website, the filter intercepts the request and checks the domain against predefined lists. The system denies blocked domains, while allowing approved ones to proceed normally.

Customization allows enforcement of specific policies, like blocking social media or adult content. Organizations can apply filters to entire networks or individual devices, with network-level implementation ensuring consistent policy enforcement.

The system operates continuously, updating its blocked domain list to adapt to emerging threats in real-time.

Importance of DNS Filtering in Cybersecurity

DNS filtering protects networks by intercepting DNS requests, blocking malicious or unwanted content before it reaches users.

Key statistics:

• Google handles 13.21% of all DNS requests
• OpenDNS follows at 1.82%
• NeuStar, Quad9, and CloudFlare handle smaller portions (0.15%, 0.13%, and 0.12% respectively)
• Only 15% of DNS requests use one of these top providers

Here’s Why DNS Filtering Matters for Cybersecurity:

Here are the reasons why DNS filtering matters.

1. Foundation of Network Security

DNS filtering forms the backbone of modern cybersecurity strategies. 

Organizations depend on it as a foundational layer of protection, shielding their networks from a wide array of online threats and malicious content.

2. Proactive Threat Mitigation

A website receives an average of 94 attacks per day. Such cyberattacks often begin with unsuspecting users accessing compromised websites. 

DNS filtering preemptively blocks these dangerous sites, significantly reducing the likelihood of:

• Malware infections
• Successful phishing attempts
• Potential data breaches

It also disrupts malware communication channels, limiting internal network spread.

3. Workplace Efficiency & Compliance

In corporate settings, DNS filtering boosts productivity by restricting access to time-wasting websites. 

It simultaneously ensures adherence to organizational policies and industry regulations by managing access to inappropriate or restricted online content.

4. Safeguarding Distributed Workforces

DNS filtering extends network security beyond office walls. 

It protects remote employees accessing company resources from home networks or public Wi-Fi hotspots, where standard security measures may fall short.

5. Nurturing Safe Digital Learning

Educational institutions use DNS filtering to promote secure online learning environments. It shields students from inappropriate material and safeguards young internet users from various online risks.

6. Adaptive Security Measures

DNS filtering provides robust protection against emerging threats. 

Regularly updated filter lists incorporate newly identified malicious domains, ensuring continuous security as digital threat evolves.

7. Efficient Security Investment

Compared to many other cybersecurity solutions, DNS filtering offers a straightforward and economical implementation. 

Operating at the network level, it provides complete device protection without requiring individual software installations.

Benefits of DNS Filtering for Organizations

DNS filtering provides advantages across various aspects of IT management:

#1: Enhanced threat protection

• Decreases data breach risks
• Safeguards sensitive information

#2: Significant cost savings

• Avoids financial impacts of malware and ransomware attacks
• Economical solution for companies of all sizes

#3: Improved regulatory compliance

• Supports compliance with industry regulations
• Reduces non-compliance penalty risks
• Offers customizable settings for specific needs

#4: Increased employee productivity

• Ensures access to only approved and work-related sites
• Eliminates distractions from non-work-related websites

#5: Optimized network performance

• Improves network speeds by reducing unnecessary traffic
• Frees up IT resources for other important tasks

#6: Strengthened brand reputation

• Prevents accidental access to inappropriate content
• Increases stakeholder trust

#7: Centralized web access management

• Provides a platform to control and monitor web traffic 
• Allows easy implementation of policies across multiple locations
• Offers real-time monitoring and reporting capabilities

The Role of DNS Filtering for Managed Service Providers (MSPs)

DNS filtering is a valuable tool for Managed Service Providers (MSPs), enhancing their ability to protect and manage client networks. 

The technology offers several advantages for MSPs:

Enhanced Network Security

Protective measures work without requiring significant changes to existing infrastructure, making DNS filtering an efficient security solution for diverse client networks.

Policy Enforcement

Restrictions on non-work related websites and custom rule sets for different user groups ensure tailored protection across varied client environments.

Simplified Management

Quick detection and response to emerging threats, along with on-the-fly policy adjustments, enhance overall efficiency and responsiveness in security management.

Value-Added Service

Reliable protection for clients positions DNS filtering as an indispensable component of the security toolkit, enhancing the overall value proposition for MSPs.

Proactive Threat Prevention

Proactive blocking of known malicious domains reduces the risk of successful attacks and minimizes the need for reactive measures.

Customizable Protection

Customization options allow for precise control over internet access, balancing security requirements with business productivity across different client sectors.

Compliance Support

Blocking access to prohibited content and maintaining detailed logs assists in meeting legal and regulatory requirements for internet usage.

5 Advanced Technologies in DNS Filtering

Implementing DNS security allows companies to shift towards proactive defense strategies, addressing these widespread and expensive risks head-on.

#1: Machine Learning Integration

Machine learning algorithms are now a cornerstone of modern DNS filtering solutions. Analyzing extensive data sets in real time allows these systems to identify patterns and detect threats with greater accuracy.

#2: Artificial Intelligence for Predictive Threat Detection

Artificial intelligence enhances DNS filtering through predictive threat detection. Behavioral analysis helps to identify and block emerging threats, particularly those associated with zero-day vulnerabilities.

#3: Encryption with DNS over HTTPS (DoH) and DNS over TLS (DoT)

Encryption protocols like DNS over HTTPS (DoH) and DNS over TLS (DoT) add a critical layer of security. Encrypting DNS queries prevents unauthorized interception and manipulation, preserving privacy and integrity.

#4: Cloud-Based DNS Filtering

Cloud-based solutions offer significant advantages in managing and scaling DNS filtering. Centralized control across multiple locations and devices ensures consistent enforcement of security policies.

#5: Real-Time Threat Intelligence Integration

Integrating real-time threat intelligence feeds into DNS filtering systems brings the latest information on malicious domains directly into the filtering process. 

Faster and more accurate threat detection is achieved through this integration.

7 Challenges and Limitations of DNS Filtering

While powerful, DNS filtering faces several challenges that can limit its effectiveness.

Understanding these limitations is essential for maximizing its benefits in cybersecurity strategies.

#1: Challenges with Encrypted DNS Traffic

Encrypted DNS traffic presents significant hurdles for DNS filters in inspecting and blocking harmful content. Maintaining network security becomes more complex as encryption protocols become widespread.

#2: False Positives in Filtering

DNS filtering sometimes mistakenly blocks legitimate sites, leading to disruptions and user frustration. Continuous refinement of filtering rules is essential to minimize these false positives.

#3: Keeping Up with New and Dynamic Domains

The constantly changing domain poses a challenge for DNS filters. Regular updates to threat databases are crucial to maintaining full coverage and prompt threat response.

#4: Bypass Techniques Using Alternative DNS Servers or VPNs

Technically savvy users can bypass DNS filtering through alternative DNS servers or VPNs. It reduces the effectiveness of filters across networks and necessitates additional controls.

#5: Limited Coverage of Encrypted Content

Encrypted web content often escapes the reach of traditional DNS filters, limiting their ability to block malicious sites using HTTPS or other encryption methods.

#6: Dependency on External Threat Databases

Reliance on external threat databases introduces risks if those databases are not frequently updated. Protection gaps can emerge if organizations fail to continuously refresh threat intelligence.

#7: Impact on Network Performance

DNS filtering adds processing overhead that can affect network performance, especially in high-traffic environments. Managing latency and ensuring efficiency requires careful optimization.

10 Best Practices for Implementing DNS Filtering

Here are key practices to consider when setting up and managing DNS filtering in your organization:

#1: Choose a reliable DNS filtering provider 

Select a reputable DNS filtering service with a track record of security and performance. Consider factors like update frequency, false positive rates, and customer support.

#2: Customize filtering rules 

Tailor your DNS filtering rules to match your organization’s specific needs and policies. It may include blocking categories of websites, specific domains, or creating allow lists for necessary resources.

#3: Implement at the network level 

Apply DNS filtering at the network level to ensure all devices are protected, including those brought by employees or guests.

#4: Use encrypted DNS protocols 

Implement DNS over HTTPS (DoH) or DNS over TLS (DoT) to protect DNS queries from interception and manipulation.

#5: Regularly update block lists 

Keep your block lists current by frequently updating them with the latest threat intelligence. It helps protect against newly discovered malicious domains.

#6: Monitor and analyze logs 

Regularly review DNS filtering logs to identify potential security issues, policy violations, or attempts to bypass the filter.

#7: Educate users 

Inform employees about the DNS filtering system, its purpose, and how it affects their internet usage which can reduce confusion and support requests.

#8: Test thoroughly before full deployment 

Before rolling out DNS filtering across your entire network, conduct thorough testing to identify and address any issues or unintended blockages.

#9: Have an exception process 

Establish a clear process for users to request access to blocked sites that may be necessary for their work.

#10: Integrate with other security tools 

Combine DNS filtering with other security measures like firewalls, antivirus software, and intrusion detection systems for a more thorough security approach.

Create a Bulletproof Security Strategy with Perimeter81

With Perimeter81’s DNS filtering solution, you can protect your network from cyber threats, while seamlessly integrating it with your existing infrastructure. Perimeter81 ensures a secure environment for all users by blocking access to malicious websites before they reach your systems.

Ready to take control of your network security? 

Schedule a demo with Perimeter81 today and discover how our DNS filtering solution can safeguard your business from growing cyber threats.

FAQs