# WHATPORT(9621)

## NAME

port 9621 — Unassigned — No IANA assignment, no documented service — an unclaimed high port.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA has no registration for 9621 on TCP or UDP, and Nmap records it as `unknown` at a very low frequency. Nothing standard, no product default, and no well-documented malware claims it. A listener here is an application that picked an arbitrary free port, so the useful move is to find the owning process rather than look the number up.

## EXPOSURE

**Expose with care.** Unknown service, unknown risk. Identify the process first; an unlabelled high port is frequently something that was never meant to leave localhost.

## CHECK

```sh
sudo lsof -nP -iTCP:9621 -sTCP:LISTEN
```

## SEE ALSO

- iana — [IANA Service Name and Transport Protocol Port Number Registry](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml) (iana.org)

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HTML: <https://whatport.net/9621/> · JSON: <https://whatport.net/9621.json> · full dataset: <https://whatport.net/ports.json>