DNS-over-TLS (DoT) is a simple but powerful way to keep your internet browsing private. Think of it like turning your open letter (traditional DNS) into a locked envelope (DoT) that only you and the DNS server can open.

Standardized as RFC 7858, DoT secures your DNS (Domain Name System) queries by encrypting them with the TLS (Transport Layer Security) protocol – the same encryption used to secure websites.

In this article, we’ll explain what DoT is, how it works, why it’s important, and how you can use it with Control D to protect your browsing.

Summary:

• Encrypts DNS traffic – Sends DNS queries through a secure TLS tunnel (port 853), preventing spying or tampering
• Increases privacy and security – Stops others from seeing or changing your DNS requests
• Used at the system level – Works at the operating system or network level, not just inside your browser like DNS-over-HTTPS
• Better control – Easier to manage for families or IT teams looking to enforce filters
• Works with Control D – Combine DoT with Control D for malware blocking and content filtering for both privacy and control

What is DNS-over-TLS (DoT)?

DNS-over-TLS is a network security protocol that encrypts your queries using Transport Layer Security (TLS). TLS is the same technology that powers HTTPS. Instead of sending DNS lookups in plain text over port 53, DoT wraps them in an encrypted tunnel over port 853, making it nearly impossible for third parties to see or modify them.

DoT works at the operating system or network level. This means all applications and services benefit from DNS encryption, not just your browser.

TLS ensures:

• Encryption – so data can't be read by third parties.
• Authentication – to verify the server is who it claims to be.
• Integrity – to ensure data hasn’t been tampered with.

What Is DNS?

Let’s take a quick step back and briefly explain what DNS is.

DNS stands for Domain Name System. When you type a website into your browser like example.com, your computer needs to translate it to an IP address first before it can load the website. 

So, it asks a DNS server: “What’s the IP for example.com?” The server answers, and now your computer can connect to the right site. But by default, these DNS lookups are unencrypted, meaning anyone watching your network can see what websites you’re looking up. That’s a big privacy issue.

How Does DNS-over-TLS Work? A Step-by-Step Overview

1. You type example.com into your browser
2. Your device attempts to connect to a DoT-compatible DNS resolver (like Control D) on port 853 to find the website’s IP address.
3. A TLS handshake takes place. This verifies the identity of the server using certificates and sets up encryption keys.
4. Once the encrypted tunnel is established, your device sends DNS queries through it.
5. The DNS resolver processes the request and sends back the answer, also encrypted.
6. Your device now has the IP address it needs and connects to the website.

All of this happens in milliseconds.

Why DNS-over-TLS Matters (Top 5 Benefits)

There are several important reasons why DoT matters for your DNS security and privacy.

✅ DNS Encryption / Encrypted DNS Queries

DoT prevents ISPs, network admins, hackers on public Wi-Fi, and others from viewing your DNS traffic and reading what websites you’re looking up. This protects your browsing history from being logged or sold.

✅ Stops DNS Tampering

DoT defends against man-in-the-middle attacks, where attackers hijack your DNS queries to redirect you to fake or malicious sites. DoT prevents this by making sure only the real DNS server can answer your DNS request.

✅ System Level Protection

Unlike browser-based DoH, which only protects browser traffic, DoT secures DNS at the system level for the entire device or network. That includes apps, operating system services, background processes, and IoT devices

✅ Ideal for Enterprise and Router Configs

DoT is easier to implement in firewalls, enterprise routers, and DNS-forwarding systems compared to DoH, making it easier to manage network security and filtering across all devices.

✅ More Transparent for Admins

DoT is easier to monitor, manage, and audit because it uses a dedicated port and avoids mixing DNS traffic with normal web browsing.

Downsides and Considerations of DNS-over-TLS (DoT)

❌ Easier to Block

Because DoT uses a fixed port (853), it's easier for restrictive networks, firewalls, or countries to detect and block compared to DoH, which hides inside port 443 traffic.

❌ Not Built Into Browsers

Unlike DoH, DoT is not embedded in browsers like Firefox or Chrome. It requires configuration at the device or network level, which may be a bit harder for average users.

❌ Some Public Networks Strip It

Captive portals (like those at airports or hotels) may break DoT connections or redirect them, preventing DNS resolution entirely until you accept the terms of service.

❌ Still Not Anonymous

DoT hides your DNS lookups but not your IP address or browsing activity. You’ll need a VPN for full privacy.

DNS-over-TLS (DoT) vs DNS-over-HTTPS (DoH)?

DNS-over-TLS (DoT) and DNS-over-HTTPS (DoH) both encrypt your DNS traffic, but they work very differently. Choosing the right one depends on your specific needs.

Both offer privacy by encrypting DNS, but DoT works better for full-device or network protection, while DoH is easier for browser-only setups.

How DoT Affects DNS Filtering

Because DoT encrypts DNS traffic, traditional filters based on regular DNS may not work unless the DNS filtering platform supports DoT itself.

With a tool like Control D, you can use DoT and keep DNS filtering, logging, and content rules. That means you get privacy and control in one place.

Why Control D and DNS-over-TLS (DoT) Are the Best Combo for Secure Browsing

Control D is more than just a DNS resolver. It’s a modern, customizable DNS management service that provides full privacy and filtering. When used with DNS-over-TLS, it gives you:

• Encrypted DNS traffic that no one can spy on
• Malware, phishing, and ad & tracker blocking to keep your business safe from threats
• Content filtering to block specific content categories, or specific apps and domains
• Device or network-wide setup using routers or OS-level tools
• Multi-Tenancy for device, user, team, or client management
• Powerful analytics to log, audit, and manage your network traffic
• No additional software or hardware required

Control D supports DoT across all endpoints, so you can choose privacy without giving up security or control.

How to Enable DNS-over-TLS (DoT) with Control D: Complete Guide

Enabling TLS encryption across your internet traffic is easier than you might think. This step-by-step guide walks you through how to do it with Control D.

Step 1: Sign Up

Start by heading over to Control D and signing up for a free 30-day trial account (no credit card required).

Once registered, you’ll get full access to powerful privacy tools, including DNS encryption, rule-based content filtering, real-time analytics, and more.

Step 2: Set Up Your Custom Profile

Navigate to Profiles → Add Profile.

Give your profile a name – something like “Encrypted DNS” – and click Create.

From here, click the Profile to apply categories of content filtering that will pair with TLS for extra security. Recommended filters include:

• Malware – Blocks websites that spread harmful software like viruses, ransomware, or spyware
• Phishing – Blocks fake websites that try to trick you into giving away passwords or personal information
• Adult Content – Blocks websites with inappropriate or explicit material in any category
• Ads and Trackers – Blocks ads and scripts that track your online activity from resolving

This profile becomes the policy that all devices on your network will follow once TLS encryption is enabled.

Step 3: Create a Secure Endpoint

Now let’s create an Endpoint that you can enforce that Profile on.

Navigate to Endpoints → Add Endpoint.

Select Server and name your Endpoint, for example “Office-Router”, and assign it the Profile you just made.

Once you’ve created your Endpoint, Control D will generate unique resolver settings, including your DoT address. Copy the DoT resolver URL listed.

Step 4: Configure Your Router to Use DNS-over-TLS

Although most operating systems support DoT natively, it requires some technical expertise. For the purpose of this article, we recommend enabling DoT on your router, as it will be significantly easier and will implement DNS encryption on every device on your network.

How to Enable DoT on Your Router:

1. Log into Your Router: Open your web browser and enter your router’s IP address 
2. Find DNS Settings: Look for a section labeled DNS, Network, or WAN settings. It varies by router model.
3. Enter DoT Resolver URL: In the DoT hostname or server name fields, enter the Control D DoT Resolver URL address.
4. (Optional) Save and Reboot: Your router may require a reboot to apply the changes. 

Step 5: Verify It’s Working

After you set up TLS on your network, all your DNS requests will be encrypted and go through your custom Control D settings.

To see if it’s working, navigate to the Analytics tab in your Control D dashboard. 

There, you’ll find live logs that show which websites are being allowed or blocked. If you see traffic showing up, that means TLS is working and your network is using Control D.

When Should You Use DNS-over-TLS (DoT)?

DNS-over-TLS is a strong fit for:

• Businesses and schools that need visibility and encryption for auditing, compliance, and malware protection
• Public Wi-Fi browsing to keep your traffic hidden from snoops
• Routers & IoT devices that often send unencrypted DNS queries
• Environments where DoH is blocked or unsupported
• Home networks that want to secure DNS for all family devices

Security Myths About DNS-over-TLS (DoT)

A few things to keep in mind:

• DoT does not hide your IP address – it only encrypts the domain names you look up
• DoT does not hide traffic – It protects DNS lookups, not your full internet activity
• DoT does not make you anonymous – your traffic can still be tracked unless you use a VPN or similar tool.
• Not all DoT providers respect privacy – some log data, sell info, or block certain sites. Control D does not.

Final Thoughts

DNS-over-TLS is a strong upgrade to your online privacy. It hides your DNS lookups, protects against snooping, and works at the system level, not just your browser.

When combined with Control D, you get more than just encrypted DNS; you get the power to control what your network resolves, block threats before they reach your devices, and monitor what’s happening without sacrificing speed or simplicity.

Frequently Asked Questions (FAQ)

DoT vs VPN: What’s the difference?

DNS-over-TLS encrypts only your DNS queries, hiding which websites you look up. A VPN encrypts all your internet traffic and hides your IP address, offering broader privacy.

Does DoT work in browsers?

Not directly. DoT runs at the system or router level, so it protects all apps on your device, not just your browser, like DoH does.

Is DNS-over-TLS secure?

Yes. DoT uses strong encryption (TLS) to protect DNS traffic from being read or altered by anyone on the network.

Can DoT block ads or malware?

No, DoT only encrypts DNS traffic. To block ads, trackers, or malicious sites, you need DNS filtering features, like those offered by Control D.

Will DoT slow down my connection?

There may be a very slight delay due to encryption, but most users won’t notice any difference in browsing speed.

Does DoT hide my IP address?

No. DoT secures your DNS lookups, but your IP address remains visible. Use a privacy-focused VPN to hide your IP address..

Can DoT be blocked?

Yes. Because it uses a unique port (853), some networks or firewalls can detect and block DoT traffic.

How do I set up DoT with Control D?

Just create a profile, enable filters, generate a DoT endpoint, and paste it into your device or router settings. It’s easy and works system-wide. See full setup steps above.