Node addresses may be Tailscale DNS names (e.g., rift.scylla-hammerhead.ts.net:9444) but MCNS needs an IPv4 address for A records. The master now resolves the hostname via net.LookupHost before passing it to the DNS client. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>