Quad9

Quad9 is a free, privacy-focused DNS service that emphasizes security by blocking access to malicious domains. Operated by the non-profit entity Quad9 Foundation, it provides DNS resolution with built-in security filtering while maintaining a strict no-logging policy.

Overview

Quad9 is a public DNS service that prioritizes security and privacy. It blocks access to domains known to be associated with malware, phishing, and other malicious activities. The service is operated by the Quad9 Foundation, a non-profit organization dedicated to providing secure and private DNS resolution.

Key Features

Security Protection

Malware Blocking: Blocks access to known malware distribution sites
Phishing Protection: Prevents access to known phishing websites
Threat Intelligence: Integration with multiple threat intelligence feeds
Real-time Updates: Regular updates to threat databases

Privacy Commitment

No Query Logging: Does not store DNS queries or user information
No User Profiling: Does not profile users based on DNS queries
Minimal Data Collection: Collects only essential operational data
Non-Profit Operation: Operated by a non-profit foundation

Performance

Global Infrastructure: Anycast network with servers worldwide
Low Latency: Optimized routing for fast response times
High Availability: Redundant infrastructure for reliability
Caching: Efficient caching mechanisms for performance

Transparency

Public Reporting: Regular transparency and privacy reports
Open Operations: Open about operational practices
Community Engagement: Engages with the security community
Independent Verification: Allows for independent verification

DNS Server Addresses

Standard DNS

IPv4: 9.9.9.9 and 149.112.112.112
IPv6: 2620:fe::fe and 2620:fe::9
Port: Standard port 53 for traditional DNS

Encrypted DNS

DNS over HTTPS (DoH): https://dns.quad9.net/dns-query
DNS over TLS (DoT): dns.quad9.net (port 853)
Alternative Endpoints: Various regional endpoints available

Security Features

Threat Intelligence Integration

Multiple Feeds: Integration with various threat intelligence sources
Real-time Updates: Continuous updates to block lists
Automated Processing: Automated ingestion of threat intelligence
Quality Control: Verification of threat intelligence sources

Blocking Categories

Malware: Known malware distribution domains
Phishing: Identified phishing websites
Botnet Command & Control: C&C server domains
Exploit Kits: Domains hosting exploit kits

Privacy Protection

No IP Address Logging: IP addresses are not stored
No Query Logging: DNS queries are not logged
No Data Sharing: No sharing of user data with third parties
Data Minimization: Collects only essential data

Comparison with Other Services

vs Cloudflare DNS

Focus: Security vs performance and privacy balance
Blocking: Proactive blocking vs optional blocking
Organization: Non-profit vs commercial
Transparency: Detailed transparency reports

vs OpenDNS

Features: Simpler service vs complex feature set
Focus: Security-first vs comprehensive security and content filtering
Privacy: Stronger privacy commitments
Cost: Completely free vs tiered pricing

vs Google DNS

Privacy: Stronger privacy commitments
Blocking: Malicious domain blocking vs no blocking
Organization: Non-profit vs commercial
Data Collection: Minimal vs more extensive collection

Technical Implementation

Infrastructure

Anycast Network: Same IP addresses announced from multiple locations
Global Points of Presence: Multiple server locations worldwide
Load Balancing: Automatic distribution of query load
DDoS Protection: Built-in protection against DNS attacks

Threat Intelligence Pipeline

Data Ingestion: Automated collection from multiple sources
Processing: Validation and normalization of threat data
Distribution: Rapid distribution to global infrastructure
Verification: Quality assurance and false positive prevention

Protocol Support

Standard DNS: Full support for traditional DNS protocols
DNSSEC: DNS Security Extensions validation
EDNS0: Extension mechanisms for DNS
Encrypted DNS: Support for DoH and DoT

Privacy Policy Details

Data Collection

No Query Storage: DNS queries are not stored
No IP Logging: IP addresses are not logged
No Profiling: No user profiling based on queries
Operational Data: Only essential operational data collected

Data Retention

Temporary Data: Any temporary data is quickly purged
No Persistent Storage: No persistent storage of user queries
Log Purging: Regular purging of any temporary logs
Minimal Footprint: Designed for minimal data footprint

Transparency Reporting

Regular Reports: Regular transparency and privacy reports
Usage Statistics: Aggregate usage statistics without personal data
Security Incidents: Reporting of security incidents
Compliance: Information about privacy regulation compliance

Configuration Methods

Operating System Level

Windows: Network adapter DNS settings
macOS: Network preferences DNS configuration
Linux: Configuration in /etc/resolv.conf or systemd-resolved
Mobile Devices: Network settings for iOS and Android

Router Configuration

Home Routers: DNS settings in router administration interface
Enterprise Routers: Advanced DNS configuration options
DHCP Integration: Automatic DNS assignment to network clients
Multiple Device Protection: Protection for all devices on the network

Application Level

Browser Settings: Some browsers support custom DNS settings
VPN Integration: DNS configuration within VPN clients
Network Applications: Application-specific DNS configuration
Mobile Apps: DNS configuration through dedicated apps

Performance Metrics

Speed and Reliability

Response Times: Optimized for fast query responses
Uptime: High availability and reliability
Global Coverage: Good performance worldwide
Caching: Efficient caching mechanisms

Security Effectiveness

Block Lists: Comprehensive and regularly updated block lists
Accuracy: High accuracy in blocking malicious domains
False Positives: Minimized false positive blocking
Bypass Prevention: Prevents bypassing of security filters

Enterprise Features

Business DNS Services

Dedicated Infrastructure: Optional dedicated infrastructure options
Custom Reporting: Enterprise-focused reporting and analytics
Priority Support: Priority support for business customers
Integration Options: Integration with enterprise security tools

Security Integration

SIEM Integration: Integration with Security Information and Event Management
Threat Intelligence: Integration with enterprise threat intelligence
Security Orchestration: Integration with security orchestration tools
Compliance Reporting: Reports for regulatory compliance

Troubleshooting Common Issues

Connectivity Problems

Firewall Settings: Ensure DNS ports are not blocked
Network Configuration: Verify DNS settings are correct
ISP Interference: Some ISPs may override DNS settings
Router Issues: Check router DNS configuration

Security Blocking Issues

False Positives: Legitimate sites may be blocked
Appeal Process: Process for reporting false positives
Bypass Options: Temporary bypass options for troubleshooting
Configuration: Ensure correct security settings are applied

Future Developments

Emerging Technologies

DNS over QUIC: Support for QUIC-based DNS queries
Enhanced Privacy: New privacy protection technologies
AI Improvements: Better machine learning for threat detection
Protocol Evolution: Support for new DNS protocols

Feature Enhancements

Advanced Filtering: More granular security filtering options
Analytics: Enhanced analytics and reporting
Integration: Better integration with other security tools
Mobile Features: Enhanced mobile-specific features

Community and Governance

Non-Profit Foundation

Mission Driven: Focus on security and privacy over profit
Community Support: Support from security community
Academic Partnerships: Partnerships with academic institutions
Industry Collaboration: Collaboration with industry partners

Transparency and Accountability

Open Governance: Transparent governance processes
Community Feedback: Regular community feedback incorporation
Security Research: Support for security research initiatives
Privacy Advocacy: Advocacy for privacy rights

Conclusion

Quad9 provides a valuable public service by offering secure, private DNS resolution with built-in protection against malicious domains. Its non-profit operation and strong privacy commitments make it an attractive option for users concerned about both security and privacy. The service continues to evolve with new features and capabilities while maintaining its core mission of providing secure and private DNS resolution for everyone.