Common connectivity issues

1. DNS Resolution Problems (No Internet Access)

Most commonly caused by incorrect DNS configurations on your devices or router. To resolve, verify that all devices are properly configured to use Pi-hole as their DNS server, and double-check your router's DNS settings.

2. Advertisement Blocking Not Working

When Pi-hole fails to block ads, it's typically due to network configuration issues or DNS cache problems. Clear your device's DNS cache to fix this (use ipconfig /flushdns on Windows, or restart networking services on macOS/Linux). Ensure Pi-hole is configured as the sole DNS server in your network.

3. Web Interface Accessibility Issues

If you can't access the Pi-hole web interface, the web server may be down or the IP address might have changed. Try restarting the web server with sudo service lighttpd restart and verify Pi-hole's current IP address.

4. FTL Service Failures

The FTL (Faster Than Light) service may stop working due to configuration corruption or system crashes. Restart the service using either pihole restartdns or sudo service pihole-FTL restart. If problems persist, consider reinstalling Pi-hole.

5. IP Address Conflicts

When another device claims Pi-hole's IP address, network conflicts occur. Resolve this by assigning Pi-hole a static IP address outside your network's DHCP range.

6. Incorrect Site Blocking and False Positives

Overly aggressive blocklists can cause legitimate websites to be blocked. Address this by whitelisting specific domains through the Pi-hole administrator interface.

7. Post-Reboot Connectivity Issues

If Pi-hole isn't responding after system reboots, the service may not be starting automatically. Enable automatic startup using sudo systemctl enable pihole-FTL.

8. Degraded Internet Performance

Slow browsing can result from upstream DNS provider issues or excessive query volume. Try switching to different upstream DNS providers or analyze Pi-hole's query logs to identify problematic domains.

9. DNS Security Leaks

When devices bypass Pi-hole by using alternative DNS servers, it creates security vulnerabilities. Prevent this by configuring your router to force all devices to use Pi-hole exclusively.

10. IPv6 Configuration Problems

Incomplete IPv6 setup can cause connectivity issues. Enable and properly configure IPv6 support in your Pi-hole settings to resolve these problems.

For advanced troubleshooting, monitor your system using pihole -t or check the Pi-hole dashboard to analyze network activity and identify specific issues.