Recent Blog Posts

Diagnosing Missing DNS Glue Records and Cyclic Loops

Learn how to detect and resolve in-bailiwick circular DNS delegation failures caused by missing or mismatched glue records using dig and root traces.

Learn how to detect missing or mismatched in-bailiwick DNS glue records at the parent TLD registry using dig and command-line diagnostics.

Diagnose and resolve DNS CNAME coexistence violations (RFC 1912/2181) causing NXDOMAIN, SERVFAIL, and broken MX/TXT records across resolvers.

Resolve SERVFAIL and circular dependency resolution errors caused by missing in-bailiwick glue records in authoritative parent zone delegations.

Master SPF lookup limits, multi-string 2048-bit DKIM TXT record splitting, and strict DMARC alignment enforcement across DNS nameservers.

Architect dual-stack rDNS using RFC 2317 classless in-addr.arpa and IPv6 nibble-based ip6.arpa PTR records for edge nodes and mail deliverability.

Diagnose and resolve RFC 7208 SPF lookup limits, DKIM body hash mismatches, and strict DMARC identifier alignment failures in production DNS.

Optimize Unbound DNS resolver performance with thread pinning, SO_REUSEPORT, aggressive NSEC caching, and memory tuning on production Linux.

Optimize PowerDNS Authoritative Server using the LMDB backend. Step-by-step performance tuning for high query volume and minimal latency.