AdBlock | VPN DUO

How AdBlock Works

AdBlock works at the DNS level. Instead of modifying webpages or inspecting the content of your internet traffic, VPN DUO uses a DNS filtering service powered by Blocky to identify and block requests to domains that are known to serve advertisements, tracking technologies, or other unwanted content.

1

You connect to VPN DUO

Your device establishes a secure VPN connection to a VPN DUO server.

2

DNS requests go through the VPN

When an application or website needs to connect to a domain, it performs a DNS lookup to determine the corresponding server address.

3

Blocky checks the requested domain

VPN DUO's DNS filtering server, powered by Blocky, checks the requested domain against configured blocklists.

4

Known unwanted domains are blocked

If the requested domain matches a configured blocklist, the DNS request is blocked and the connection to that domain cannot be established.

5

Allowed domains continue normally

If the requested domain is not blocked, the DNS request is resolved normally and the connection proceeds.

Example

A webpage may contain content from several different domains. AdBlock evaluates these domain requests individually.

Website requests

example.com ads.example.net tracker.example.org cdn.example.com

→

DNS filtering result

✓ Website content × Advertising × Tracking ✓ CDN content

What AdBlock Can Block

Depending on the configured blocklists, AdBlock may block domains associated with:

Advertising domains
Known tracking domains
Analytics and telemetry domains
Some malicious or suspicious domains
Other known unwanted domains

The effectiveness of blocking depends on the configured blocklists and the domains used by individual websites and applications.

What AdBlock Does Not Do

VPN DUO AdBlock is primarily a DNS-based filtering system.

It does not modify the content of webpages.
It does not remove advertisements directly from webpage HTML.
It does not inspect the contents of HTTPS connections.
It does not guarantee that every advertisement will be removed.
It does not guarantee that every tracker will be blocked.
It cannot reliably block advertisements served from the same domain as legitimate content.

Privacy

VPN DUO is designed to provide DNS-based filtering without requiring the contents of your web traffic to be inspected.

AdBlock operates by evaluating DNS requests against configured blocklists. It does not need to read the contents of your HTTPS traffic to perform domain-level blocking.

DNS filtering may require processing the domain names requested by your device so that the filtering service can determine whether a domain should be allowed or blocked.

VPN DUO uses this information for the purpose of providing and operating the DNS filtering functionality and does not use the contents of your web traffic for advertising purposes.

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DNS-level filtering

AdBlock works at the domain/DNS level rather than inspecting the actual content of websites, HTTPS requests, or encrypted application traffic.

For more information about how VPN DUO handles personal information, please refer to our Privacy Policy.

Blocklists

Blocky uses configured DNS blocklists to determine which domains should be blocked.

Blocklists can change over time as new advertising, tracking, malicious, and unwanted domains are identified.

As a result, the behavior of AdBlock may change without requiring an application update.

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Blocklists are continuously evolving

No blocklist can identify every advertising, tracking, or malicious domain. Some websites and applications may also use techniques that make DNS-level blocking less effective.

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Important: Double VPN + IKEv2

AdBlock is currently not supported when using Double VPN with the IKEv2 protocol.

If you are using Double VPN + IKEv2, VPN DUO's AdBlock functionality will not be available because this configuration does not currently support DNS-based AdBlock filtering.

To use AdBlock, connect using other supported VPN DUO connection configuration instead of Double VPN + IKEv2.

Why this limitation exists

AdBlock depends on VPN DUO's DNS filtering configuration being available to the active VPN connection.

The current Double VPN implementation using IKEv2 does not provide the required DNS filtering support.

This is a technical limitation of the current Double VPN + IKEv2 configuration and does not affect AdBlock when using supported VPN configurations.

AdBlock and Your VPN Connection

AdBlock works as part of the VPN DUO network configuration. Therefore, the availability of AdBlock depends on the VPN protocol and connection configuration you are using.

If AdBlock is not working

If AdBlock is enabled but does not appear to be working, check the following:

You are connected to a VPN DUO server.
AdBlock is enabled.
You are not using Double VPN with the IKEv2 protocol.
The requested domain is included in the configured blocklists.

Limitations

DNS-based AdBlock cannot guarantee complete removal of all advertisements or trackers.

Blocking may be less effective when:

Advertisements are hosted on the same domain as legitimate content.
A website uses first-party advertising.
An application embeds advertisements directly into its content.
A domain has not yet been added to the blocklists.
A website changes its advertising or tracking infrastructure.
An application uses DNS mechanisms that bypass the VPN's DNS filtering.

Complete blocking cannot be guaranteed

VPN DUO continuously works to improve the effectiveness of its DNS filtering configuration, but complete blocking of all advertisements, trackers, or unwanted domains cannot be guaranteed.

Changes to AdBlock

We may update the DNS filtering configuration and blocklists from time to time to improve performance, privacy, security, and blocking effectiveness.

These changes may alter which domains are blocked or allowed without requiring an update to the VPN DUO application.

Contact

If you believe a legitimate website or service is being incorrectly blocked, or if you encounter an issue with AdBlock, please contact VPN DUO support with the relevant details so that we can investigate the issue.

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Need help?

When contacting support, please include the affected website or application, the VPN configuration you are using, and a description of the issue. You can contact us at: support@techlancersltd.com.

Our Approach

VPN DUO AdBlock is designed to provide an additional layer of privacy and protection while browsing, while keeping the filtering process focused on DNS-level domain requests rather than inspecting the contents of your internet traffic.