# WHATPORT(18101)

## NAME

port 18101 — Unassigned — Unregistered; the only true statement about a listener here is that something picked the number.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA does not assign 18101 — the closest registration in the range is 18104 (radpdf, RAD PDF Service), which is a different port. Nmap has no service name for 18101 and scans it by default only because its measured open-port frequency puts it in the top 1000. No widely deployed software documents it as a default.

## EXPOSURE

**Expose with care.** No known protocol means no known authentication or encryption story. Fingerprint before you decide, and default to closed at the perimeter.

## CHECK

```sh
nmap -Pn -sV -p 18101 TARGET
```

## 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)
- source — [Nmap services frequency database](https://github.com/nmap/nmap/blob/master/nmap-services) (github.com)

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HTML: <https://whatport.net/18101/> · JSON: <https://whatport.net/18101.json> · full dataset: <https://whatport.net/ports.json>