# WHATPORT(1011)

## NAME

port 1011 — Reserved (IANA) — Part of IANA's reserved 1011–1020 block — held back deliberately, so no service will ever be registered here.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA marks the whole 1011–1020 range Reserved, which is a stronger statement than Unassigned: these numbers are held back and not handed out. No standard service exists or will exist on 1011, and nmap lists it as unknown with a very low open rate. Anything listening is a purely local decision, made by a privileged process since the port is inside the system range.

## EXPOSURE

**Expose with care.** A reserved port with a listener on it is by definition something nonstandard running with root privileges. Identify it; there is no registry entry to fall back on.

## CHECK

```sh
sudo lsof -nP -iTCP:1011 -sTCP:LISTEN
```

## SEE ALSO

- iana — [IANA Service Name and Transport Protocol Port Number Registry (1011–1020 Reserved)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml) (iana.org)
- spec — [RFC 6335 — IANA procedures for port number assignment](https://www.rfc-editor.org/rfc/rfc6335.html) (rfc-editor.org)

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HTML: <https://whatport.net/1011/> · JSON: <https://whatport.net/1011.json> · full dataset: <https://whatport.net/ports.json>