# WHATPORT(7921)

## NAME

port 7921 — Unassigned — IANA has never assigned this port, and no common service is known to squat it.

Protocol: TCP  
IANA registry

## DESCRIPTION

7921 falls inside the block IANA lists as 7914-7931 Unassigned, so there is no registered service name to look up. Nmap's service database has no name for it either and files it as `unknown`, seen on roughly two hundredths of a percent of scanned hosts. In practice that means anything listening here is some application's private choice of port, not a standard protocol. Identify it by its banner rather than by the number.

## EXPOSURE

**Expose with care.** An unregistered port tells you nothing about safety — find out what the listener actually is before deciding, and treat an unidentified internet-facing service as untrusted.

## CHECK

```sh
nmap -sV -Pn -p 7921 TARGET
```

## SEE ALSO

- iana — [IANA Service Name and Transport Protocol Port Number Registry — 7921](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=7921) (iana.org)
- source — [nmap/nmap — nmap-services (port frequency database)](https://github.com/nmap/nmap/blob/master/nmap-services) (github.com)

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HTML: <https://whatport.net/7921/> · JSON: <https://whatport.net/7921.json> · full dataset: <https://whatport.net/ports.json>