Why it matters
Most threats start with a click. Stopping connections at the DNS layer cuts off malware downloads, command-and-control beacons, and fake login pages -without slowing users or breaking trusted sites.
How it works
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Your device asks DNS for a site’s address.
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The resolver compares the domain to threat feeds and your rules.
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Allowed domains resolve normally; blocked domains return nothing or a safe page.
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Categories (malware, phishing, adult, piracy, crypto-mining) make policy easy.
Good uses
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Security: block malware/phishing and C2 call-outs by default.
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Compliance & productivity: restrict categories at work/school.
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Home safety: filter adult content and scam sites across all devices.
Limits to know
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Doesn’t see IP-only traffic or traffic sent through some VPNs.
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Users can try alternate DNS unless you enforce it on the network.
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False positives happen—keep an allowlist and review logs.
Quick setup
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Pick a reputable DNS filtering service with categories and custom lists.
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Force all DNS to your resolver at the router/firewall; block outbound 53/853 to others.
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Enable DoH/DoT to your chosen resolver to prevent tampering.
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Start in monitor mode for a week, review hits, then enforce.
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Maintain allow/deny lists; alert on malware/phishing blocks.