DNS Interception Technology: Blocking Gambling at Network Level

Whistl's DNS interception blocks gambling websites before they load—across all browsers and apps on your device. Using VPN-based DNS filtering, Whistl prevents access to thousands of gambling domains while displaying supportive intervention messages instead of error pages.

Understanding DNS and How Blocking Works

To understand DNS interception, first understand how DNS works:

What Is DNS?

DNS (Domain Name System) translates human-readable domain names to IP addresses:

• You type: sportsbet.com.au
• DNS resolves to: 104.18.32.167
• Your browser connects to that IP address

DNS is the "phonebook" of the internet—without it, you'd need to memorise IP addresses.

How DNS Interception Blocks Gambling

Whistl intercepts DNS queries before they reach the internet:

# Normal DNS flow (no blocking)
User types "sportsbet.com.au"
    ↓
Device sends DNS query
    ↓
DNS server resolves to IP
    ↓
Browser loads website

# Whistl DNS interception (blocking active)
User types "sportsbet.com.au"
    ↓
Device sends DNS query
    ↓
Whistl VPN intercepts query
    ↓
Domain is on blocklist? YES
    ↓
Return intervention page IP instead
    ↓
User sees Whistl support message, not gambling site

Whistl's VPN-Based DNS Filtering

Whistl uses a local VPN configuration to intercept DNS queries:

How the VPN Works

• Local VPN: Traffic stays on your device (not routed through external servers)
• DNS filtering only: Only DNS queries are processed, not full traffic
• Privacy-preserving: Browsing data is not collected or transmitted
• System-wide: Works across all browsers and apps

VPN Configuration

When you enable DNS blocking in Whistl:

1. iOS prompts for VPN permission
2. Whistl installs a local VPN configuration
3. All DNS queries route through Whistl's filter
4. Blocked domains return intervention page
5. Allowed domains resolve normally

The Gambling Domain Blocklist

Whistl maintains a comprehensive blocklist of gambling-related domains:

Blocklist Categories

Total blocklist: 5,000+ domains and counting

Blocklist Updates

• Weekly updates: New domains added regularly
• User submissions: Users can report unblocked sites
• Wildcard patterns: Blocks subdomains automatically
• Regex matching: Catches variations and typos

Intervention Pages Instead of Errors

Unlike simple blockers that show error pages, Whistl displays supportive interventions:

Intervention Page Content

When you try to access a blocked site, you see:

• Supportive message: "I know you want through. Let's talk about why."
• Risk level display: Current composite risk score
• Quick actions: Breathe, call partner, view goals
• Negotiation entry: Option to start 8-Step Negotiation
• Crisis resources: Gambling Help, Lifeline numbers

Intervention Page Example

┌─────────────────────────────────────────┐
│  Whistl                                 │
│                                         │
│  This site is blocked for your          │
│  protection.                            │
│                                         │
│  Your current risk level: HIGH          │
│                                         │
│  I know you want through. Let's talk    │
│  about what's driving this.             │
│                                         │
│  [ Breathe ]  [ Call Partner ]          │
│  [ View Goals ]  [ Start Negotiation ]  │
│                                         │
│  Need immediate support?                │
│  Gambling Help: 1800 858 858            │
│  Lifeline: 13 11 14                     │
└─────────────────────────────────────────┘

When DNS Blocking Activates

DNS blocking isn't always on—it activates based on risk level:

SpendingShield State Integration

Manual Override

Users can manually control DNS blocking:

• Always on: Continuous protection
• Scheduled: Active during high-risk hours
• Event-triggered: Activates when risk score exceeds threshold
• Temporary disable: 15-minute window for legitimate needs

Privacy and Security

Whistl's DNS interception is designed with privacy as a priority:

What Whistl Does NOT Do

• No browsing history collection: Only domain names are checked
• No traffic inspection: Content is never viewed
• No data transmission: DNS queries processed locally
• No third-party sharing: Data stays on device

What Whistl DOES Track

• Blocked domain count: Number of block attempts
• Query timestamps: When blocking occurred
• Domain categories: Type of site attempted

This data is used only for personal insights and risk calculation—never transmitted externally.

Setting Up DNS Blocking

Enabling DNS blocking in Whistl is straightforward:

Initial Setup

1. Open Whistl app settings
2. Tap "DNS Blocking & VPN"
3. Toggle "Enable DNS Blocking"
4. Accept iOS VPN permission prompt
5. Select blocking level (Conservative, Balanced, Aggressive)
6. Blocking is now active based on your risk state

Customising Blocklist

• Add custom domains to block
• Whitelist specific domains (rare, for false positives)
• Select categories to block
• Set different blocking levels for different states

Effectiveness Data

From users with DNS blocking enabled:

User Testimonials

"The intervention page actually helps. Instead of just an error, I get support. It's made a huge difference." — Marcus, 28

"I tried to access a betting site at 2am and Whistl was there. That intervention page talked me down. Still grateful." — Jake, 31

"Works across all my browsers and apps. No loopholes. Finally something that actually blocks." — Emma, 26

Conclusion

DNS interception represents network-level protection that works across your entire device. By blocking gambling domains before they load and replacing errors with supportive interventions, Whistl turns every block attempt into an opportunity for support.

This isn't just blocking—it's intelligent, compassionate protection that meets you at the moment of vulnerability.

Related: SpendingShield | 8-Step Negotiation Engine | Privacy-First AI