The Essential Guide to DNS Filtering for Businesses

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Hi there! As a cybersecurity analyst, I wanted to provide you with a comprehensive guide to DNS filtering. This powerful technology has become critical for protecting businesses against the many threats that come from the web.

In this guide, I‘ll explain what exactly DNS filtering is, why businesses need it, its key benefits, and some best practices for implementation. My goal is to give you a detailed understanding of how DNS filtering works so you can make informed decisions around securing your business‘s networks and devices.

Let‘s get started!

What is DNS Filtering and How Does it Work?

The Domain Name System (DNS) is the backbone of the internet. It‘s like the phonebook that translates domain names we type into browsers (e.g. to the IP addresses computers need to route traffic.

DNS filtering solutions work by intercepting these DNS requests and cross-checking them against a regularly updated database of known malicious domains and IP addresses. If there is a match, the request gets blocked before a connection can be established.

This allows businesses to control what sites and content their users can access across the network. Some common categories that get filtered include:

  • Malware
  • Phishing attacks
  • Spyware
  • Explicit/adult content
  • Gambling
  • Illegal drug sites
  • Botnet C&C servers

And the best part is DNS filtering is always on. Whether users are on the corporate network, guest WiFi, at home, or a coffee shop, all DNS requests get inspected and filtered no matter where they are.

Why DNS Filtering Matters More Than Ever

The internet has changed dramatically since the early days. What was once largely harmless fun and learning has also become a prime vector for cyberattacks. Just look at these stats:

  • 90% of malware is delivered through the web – Hackers heavily leverage websites, ads and links in email/messaging to install malware.

  • 40% of enterprise breaches originate from the web – Whether it‘s compromised sites, phishing links or watering hole attacks, the web is the top infection vector.

  • 65% of companies have experienced DNS-based malware infections – Data shows DNS itself is heavily abused to direct users to malicious sites and botnet control servers.

And attackers are endlessly creative – as soon as new web or social platforms gain adoption, cybercriminals quickly follow. Remember early Facebook spam? Or malicious YouTube links? Emerging platforms like TikTok are already seeing similar patterns.

The web has simply become too risky to leave unfiltered. Just like email required new protection in the 90s as threats emerged, DNS filtering is needed now to handle the variety of web-based threats.

Key Benefits of DNS Filtering

Now that you understand the critical importance of DNS filtering, let‘s explore some of the key benefits it brings for securing businesses:

1. Real-Time Protection from Emerging Threats

New domains associated with malware, phishing scams, and other threats emerge every single day. Cisco Umbrella blocks 81 billion malicious requests per day – that‘s over 950 requests flagged per second!

The difference with DNS filtering is it uses predictive analytics to identify malicious sites early based on domain activity patterns and relationships. This provides a critical window where emerging threats can be blocked immediately versus waiting for them to be identified and blacklisted.

2. Limits Infections by Blocking Malware Downloads

Over half of company endpoints have still experienced a malware infection in the past year according to Cisco‘s 2022 security report. Much of this malware arrives from compromised websites, ads, and harmful links that download malicious payloads.

With DNS filtering inspecting all web traffic, employees are prevented from accidentally downloading malware from sites the security solution flags as harmful. This significantly reduces infections and limits the hacker tools that make it into your environment.

3. Significantly Reduces Phishing Risk

91% of cyberattacks start with a phishing email – and most contain embedded links to fake login pages hosted on compromised sites or domains registered by hackers. DNS filtering blocks employees from reaching these fake phishing sites and exposing their credentials.

In testing, Cisco Umbrella blocked 98% of phishing domains. Real-time threat intelligence prevents phishing links from becoming dangerous, adding critical protection on top of user security training.

4. Filters Explicit and Unproductive Content

Unfiltered web access often leads to employees getting distracted, wasting time, and even exposing the company to legal risks. One survey saw 70% of US workers accessing porn at work.

DNS filtering allows businesses to filter categories like explicit content, gambling, hate speech, and non-business related sites like gaming and social media. This creates a safer, more productive browsing environment for employees.

5. Gain Centralized Visibility and Policy Control

DNS filtering provides network administrators a centralized command center to see all web activity across the network. Detailed analytics around top blocked domains, traffic patterns, infection attempts and policy violations help quickly identify risks.

Granular policy customization also allows businesses to tailor internet usage to balance security and user freedom. Different policies can be applied across locations, user groups, and departments.

6. Secures Remote and Mobile Users

Traditional network security stacks focus on protecting on-premise traffic flowing through corporate devices. But in today‘s work from anywhere environment, businesses need consistent security for remote and mobile users.

DNS filtering secures these roaming users by redirecting their DNS requests to the cloud filtering service. This ensures users have the same level of protection working from home or a coffee shop as they do in the office.

7. Easy to Deploy, Maintain, and Scale

Unlike firewalls and proxies, DNS filtering is delivered through a secure cloud service that protects endpoints wherever they connect. There‘s no hardware to install or software to maintain.

Most solutions like Cisco Umbrella also have lightweight clients that can auto-deploy through existing system management tools. This makes it fast and easy to enable DNS filtering across thousands of distributed endpoints.

8. Cost-Effective Protection

Getting enterprise-grade security at an affordable cost is always a priority, especially for smaller businesses. Top DNS filtering solutions are available as annual subscriptions based on the number of user licenses.

When compared to buying and managing separate tools like proxies and sandboxing, DNS filtering provides very competitive ROI. For example, Cisco Umbrella licenses start at around $1/user/month for full web filtering capabilities.

9. Faster Performance and Reliability

Contrary to what some may think, DNS filtering does not slow your internet performance when implemented correctly. In fact, by blocking malicious domains, it actually helps websites load faster.

The top solutions like Cisco Umbrella also offer highly redundant global DNS resolvers that are miles closer to endpoints than default ISP resolvers. This reduces latency and improves reliability as there are fewer hops for DNS requests.

For many industries like healthcare and finance, DNS filtering is no longer just best practice – it‘s required. HIPAA, PCI DSS, GLBA and other regulations lay out strict guidelines around limiting threats and managing high-risk internet use.

Having auditable DNS filtering policies and reporting helps prove compliance controls are in place and being actively managed. This reduces audit complexity for covered entities.

As you can see, DNS filtering really hits on all fronts – providing robust threat protection while also improving productivity, visibility, and regulatory compliance.

5 Best Practices for Getting the Most Value from DNS Filtering

Now that I‘ve explained the value DNS filtering brings to the table, I wanted to outline some best practices for making sure you maximize the benefit:

1. Supplement Existing Defenses Rather Than Replace

The most effective security stacks utilize a layered defense model, with overlapping controls to cover blind spots. DNS filtering adds critical protection at the DNS lookup layer.

But you still need anti-malware, firewalls, gateways and other controls. It works best when integrated and combined with these other defenses.

2. Start with a Trial Deployment

Before rolling out DNS filtering for the entire organization, start with a limited trial for proof of concept. This allows you to validate it works as expected and doesn‘t cause performance/reliability issues.

It also lets you test filtering policies and fine-tune allow/block lists before enforcing across the global network.

3. Create User Groups and Custom Policies

Don‘t use a single blanket filtering policy for all users. IT admins normally need access to more sites than sales. Create groups with custom policies that meet specific department and user needs.

For example, limit engineering to technical/development sites but block gaming/social media. Make policies granular based on user risk profiles.

4. Filter Encrypted Traffic

With HTTPS encryption now commonplace, businesses need filtering capable of inspecting encrypted traffic for threats, not just openly visible DNS requests.

Ensure any solution you evaluate can filter encrypted traffic to avoid large security gaps.

5. Monitor Alerts and Analytics

Review DNS filtering alerts and usage analytics regularly to identify new risks, policy violations, and other trends. Tune your policies to current challenges based on this data.

For example, if you see an increase in blocked social media or certain sites, adjust filters accordingly. Use the intelligence gained to strengthen defenses.

Conclusion and Next Steps

I hope this guide provided you with a detailed understanding of how essential DNS filtering has become for protecting businesses in today‘s threat landscape. The central role DNS plays in directing web traffic makes it both a critical threat vector but also an extremely effective place to block those attacks.

Here are some good next steps based on where you are at in evaluating DNS filtering:

  • Just starting research? Try Cisco Umbrella‘s interactive product tour to learn more about features and see it visually in action.

  • Want to test drive it yourself? Sign up for a free 14-day Cisco Umbrella trial to experience the dashboard and policies firsthand.

  • Ready to talk to an expert? Connect with a Cisco Umbrella sales rep to discuss licensing, deployment, and policy planning for your specific environment.

I hope this guide gave you a clear understanding of the value DNS filtering delivers and how it can help take your organization‘s security stack to the next level against an increasingly dangerous web-driven threat landscape.

Let me know if any questions come up along your evaluation journey – I‘m always happy to help explain concepts and provide guidance!

Stay safe out there,

[Your Name]

Written by Alexis Kestler

A female web designer and programmer - Now is a 36-year IT professional with over 15 years of experience living in NorCal. I enjoy keeping my feet wet in the world of technology through reading, working, and researching topics that pique my interest.