4 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
NTP service discovery (_ntp._udp.<domain>): SRV records with priority, weight, port and target host, from Cloudflare DoH. Tells a client where the domain's ntp service lives without guessing hosts. $0.01 per lookup.
Is TCP port 123 (NTP) open on a host? Attempts a connection from Cloudflare's edge and reports open/closed/filtered with the connect time; Cloudflare-fronted hosts are reported as inconclusive because their edge answers...
Change watch for is port 123 open: runs the check, compares it with the result from your previous call for the same host (kept 90 days) and returns the current answer, changed true/false, the fields that changed with bef...
Bulk is port 123 open: up to 20 hosts in one call, processed concurrently, results in input order with a per-item error field and a failure count. Same answer per item as the single endpoint. Batch enrichment for agents...