knot knot

DNS

Troubleshooting DNS server issues.

DNS Not Resolving

Symptom: Cannot resolve knot domains.

Test DNS resolution:

dig @192.168.1.100 -p 3053 knot.internal
nslookup knot.internal 192.168.1.100

Verify client configuration:

# Linux
resolvectl status

# macOS
scutil --dns

# Windows
Get-DnsClientNrptPolicy

Solutions:

  • Verify DNS server is running
  • Check DNS server listen address and port
  • Ensure client is configured to use knot DNS
  • Check firewall rules allow DNS traffic
  • Verify DNS records are configured correctly

Slow DNS Resolution

Symptom: DNS queries take long time to resolve.

Solutions:

  • Check upstream nameserver performance
  • Reduce number of upstream nameservers
  • Use local caching DNS resolver
  • Check network latency to upstream servers
  • Monitor DNS server resource usage

Wildcard Domains Not Working

Symptom: Specific domains resolve but wildcard doesn’t.

Test wildcard:

dig @192.168.1.100 -p 3053 test.knot.internal

Solutions:

  • Verify wildcard record in configuration: A|*.knot.internal|IP
  • Check client DNS resolver supports wildcards
  • Test with different DNS tools
  • Verify no conflicting DNS records