NextDNS – The Firewall Against Surveillance and Censorship by Your Internet Provider

The Domain Name System (DNS) is the phone book of the internet. Without DNS, your browser has no idea which IP address is behind google.com or alien-investor.org. By default, this phone book is provided by your internet service provider (ISP) — think Deutsche Telekom or Vodafone.

The problem: whoever controls the phone book doesn't just see who you're "calling" — they can also block calls or route you to the wrong number. DNS is a critical control point for metadata (which domains you resolve) and for filtering mechanisms at the resolver level.

My current tool of choice for digital self-defense is NextDNS. Here's why you should make the switch and what it means technically.

1. The Status Quo: Your ISP Is Watching

The major providers operate in a tension between network stability, legal obligations, and commercial interests. The result for your privacy is often sobering.

Data Retention and Commerce

Even with GDPR in play, there are grey areas and mandatory security processes.

• Deutsche Telekom: Like virtually all providers, it logs and processes connection and security data (e.g. for fault analysis, abuse and attack detection). That's understandable for network operations — but it means: metadata is generated and may be retained for a limited period.
• Vodafone: Beyond operations and security, large corporations typically have processes for analytics and marketing. What matters is what you actively consent to (opt-ins). Even if "only" domains are visible, they often enable very clear conclusions about your interests and habits.

DNS Blocks: The CUII

In Germany, DNS blocks are implemented via the "Clearingstelle Urheberrecht im Internet" (CUII). The model remains controversial, because here rights holders and providers operate a blocking infrastructure. Key context: under the CUII framework, every DNS block is subject to judicial review.

Technically this works as DNS manipulation/redirection: when you try to resolve a blocked domain, you don't get the "normal" resolution — instead you're redirected to a blocking/info page from the provider (or a CUII landing page), or the resolution simply fails from the user's perspective.

Bottom line: with provider DNS, you accept an internet that can be filtered at the resolver level.

2. NextDNS: Your DNS Firewall in the Cloud

NextDNS flips the script. It's a resolver with security and privacy features: block lists, anti-phishing, anti-malware, and tracking protection — centrally managed for all your devices. (Important: this is not a VPN. It doesn't replace end-to-end encryption of your connections — it protects the DNS layer.)

Sovereignty Over Your Data

Unlike your ISP, here you control the logging.

• No-Logging: You can disable logs entirely — no logs will be generated for that configuration.
• Data Residency: If you need logs for troubleshooting, you can choose where they're stored (e.g. Switzerland). This can reduce your legal attack surface — but it's no guarantee of untouchability.

Active Defense Against Trackers (CNAME Uncloaking)

Modern trackers often disguise themselves as harmless subdomains of the website you're visiting (e.g. metrics.newspaper.com instead of tracker.adtech.com). Browser blockers can sometimes be fooled by this. NextDNS can trace the CNAME chain during resolution and apply block lists to the "hidden" targets as well — the request is blocked before it ever leaves your device.

Protection for IoT Devices

Your smart TV (Samsung, Xiaomi, etc.) and your smart light bulbs are constantly phoning home. Since you can't install an adblocker on these devices, a DNS filter is often the only practical line of defense. It blocks telemetry and tracking domains from manufacturers right at the source.

"NextDNS isn't just a phone book — it's a bouncer. You decide who gets into your network and what data goes out."

3. Performance and Technical Reality

A common argument against external DNS providers is latency (ping). In practice, this depends heavily on routing. You can test it yourself, e.g. via ping.nextdns.io (typically showing single-digit to low double-digit millisecond values — depending on your location and network).

More important than ping: Since NextDNS prevents ads and trackers from resolving in the first place, your browser often has to load far less. In everyday use, this speeds up page load times significantly more than a few milliseconds of DNS latency will cost you.

4. The Downsides: Convenience vs. Security

If you want sovereignty, you have to take responsibility. NextDNS is not a "set-and-forget" system for people who don't want to be bothered.

The False Positive Problem

Enable aggressive filter lists and you will sometimes block things you actually need.

• Banking apps: Some apps use fraud protection services that look like trackers. If those domains get blocked, the app may misbehave or fail to launch.
• Smart home: Block your smart TV's domains and you might also break updates or app stores.

You need to be willing to check the logs (if enabled) and put domains on a whitelist. That's the price of freedom.

Shift of Trust

Let's be honest: you don't eliminate the trust problem entirely — you shift it. Instead of trusting Telekom, you now trust NextDNS. The difference: you get real levers (logging off, data residency, filter logic) — and you can harden your setup transparently.

5. Implementation: How to Get Started with NextDNS

The Gold Standard: FritzBox with DNS-over-TLS (DoT)

The FritzBox is the standard router in Germany. Since Fritz!OS 7.20 it supports DNS-over-TLS (DoT). This is the best approach because it protects your entire home network in one move.

1. Create a profile on the NextDNS website.
2. In the FritzBox, go to Internet -> Account Information -> DNS Server.
3. Enable "Encrypted name resolution on the internet (DNS over TLS)".
4. Enter your NextDNS address (e.g. [Your-ID].dns.nextdns.io).
5. If your FritzBox offers a certificate verification option: enable it (so you're not redirected to a fake resolver).

Important: With DoT (or DoH), the configuration ID is transmitted in the hostname/URL. In this case, "Linked IP"/DynDNS is generally not needed. Linked IP is more of a workaround when you can only use classic DNS IPv4 addresses without an ID.

On the Go: iOS and Android

No app required for your smartphone. iOS supports native configuration profiles that hook deep into the system and run stably. Android offers a simple DoT setting (hostname) under "Private DNS". This keeps you protected on mobile networks and on foreign Wi-Fi.

6. Alien Verdict: Take Back Control

Switching to a private resolver like NextDNS is a strategic move. You reduce tracking via ISP-DNS and make DNS blocks significantly harder (or at least more visible), while simultaneously hardening your network against malware and phishing.

Yes, it takes a bit of work upfront (whitelisting). But for anyone holding Bitcoin, handling sensitive data, or simply refusing to be a transparent citizen, this step is powerful. Default settings are for tourists. Owners configure their own infrastructure.