Block threats. Control access. Protect your business at the network level

When a team member types a web address into their browser, they’re not just opening a website — they’re potentially exposing your business to risk.

DNS filtering is a simple but powerful way to prevent unsafe, unwanted or unproductive access to parts of the internet.

It helps stop malware, phishing, and inappropriate content before the page even loads.

At LeftBrain, we help fast-moving teams implement DNS filtering that is flexible, reliable and invisible to the user — unless something needs to be blocked.

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What is DNS filtering?

DNS stands for Domain Name System. It’s the service that turns “example.com” into the IP address of the server hosting that site.

DNS filtering allows you to control which websites your users can access by checking each request against a set of rules or categories.

If a site is malicious, inappropriate, or simply not part of your business needs, DNS filtering stops the connection before it reaches the browser.

Think of it as a protective layer that acts before a threat even has the chance to reach your devices.

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Why DNS filtering matters

Without DNS filtering, every device on your network has a wide-open door to the internet.

That includes sites that host malware, phishing pages, spyware, and illegal content.

DNS filtering helps you:

• Reduce the risk of ransomware and phishing attacks
• Prevent access to inappropriate or non-business sites
• Enforce acceptable use policies without monitoring individuals
• Comply with security frameworks and policies
• Protect remote and office-based teams equally

It’s especially valuable for growing teams where security needs to scale — and where not everyone knows what should or shouldn’t be clicked.

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What we do

At LeftBrain, we help you design and implement DNS filtering that fits your culture and your level of risk.

Step 1: Audit your current DNS setup

We check:

• Whether you have DNS filtering already
• How effective it is
• Whether it protects all devices (not just desktops)
• How policies are applied to staff, guests and contractors

We often find gaps in coverage or outdated tools that are no longer doing the job.

Step 2: Define your filtering policy

Together, we decide:

• Which categories of sites should be blocked (e.g. malware, adult content, illegal downloads)
• Whether specific platforms like YouTube, social media or gambling sites should be restricted
• What level of control and reporting you want
• How to handle exceptions and overrides

The goal is to protect your team without creating unnecessary blocks or frustration.

Step 3: Deploy across your environment

We configure DNS filtering across:

• Office networks and routers
• Remote devices using agent-based filtering
• Mobile and BYOD devices where possible
• Guest Wi-Fi access
• Cloud-managed dashboards for IT oversight

Everything is set up for central control and easy adjustment as your business changes.

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Tools we work with

We are not tied to one vendor. We work with a range of trusted DNS filtering solutions including:

• Cisco Umbrella
• Cloudflare Gateway
• NextDNS
• AdGuard
• DNSFilter
• Built-in options within MDM or security platforms

We help you choose based on your infrastructure, team size and security requirements.

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What DNS filtering protects against

• Phishing and impersonation sites
• Malware and drive-by downloads
• Command and control callbacks from infected devices
• Sites hosting illegal or inappropriate content
• Cryptojacking and malicious ads
• Employee access to unsafe or productivity-draining platforms

It gives your business a quiet layer of protection — one that catches problems before they escalate.

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What this unlocks for your business

For IT and ops

• Easier management of acceptable use
• Protection that works without hands-on monitoring
• Clear reports and simple controls

For leadership

• Fewer security incidents and reputational risks
• More control over network activity
• A policy you can point to during audits or client reviews

For compliance

• Support for ISO 27001, Cyber Essentials and internal security frameworks
• Network-level controls that go beyond device-based protections

For your team

• Fewer threats, less downtime
• Protected browsing without invasive controls
• The freedom to focus on work

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Why LeftBrain

We don’t just turn DNS filtering on and walk away.

We work with you to define clear rules, roll them out cleanly, and adjust them when your business evolves.

Whether you want to stop obvious threats or take more control over internet use in your business, we’ll help you do it the right way — without slowing anyone down.

“Working with LeftBrain keeps our network and data secure and saves us money in the long run, helping us to best serve and protect the intellectual property and trade secrets of our clients.”