{
  "port": 9943,
  "protocol": "tcp",
  "service": "Unassigned",
  "oneLiner": "Unregistered with IANA; nothing well-known claims it, despite sitting next to Substrate's 9944.",
  "whatItIs": "IANA lists no assignment for 9943, and Nmap's service database calls it unknown, open on about 0.03% of scanned hosts. Its neighbour 9944 is the Substrate/Polkadot JSON-RPC default, but that does not extend to 9943 — no published project defaults here. Treat anything listening as a custom or ad-hoc service and identify it by banner rather than by number.",
  "exposure": {
    "verdict": "careful",
    "note": "No registration means no assumptions. Determine what the listener actually is, and whether it authenticates, before exposing it."
  },
  "checkCommand": "nmap -sV -p 9943 TARGET",
  "links": [
    {
      "title": "IANA port registry — 9943 (no assignment)",
      "url": "https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=9943",
      "kind": "iana"
    },
    {
      "title": "nmap-services — Nmap's port frequency database",
      "url": "https://github.com/nmap/nmap/blob/master/nmap-services",
      "kind": "github"
    }
  ]
}