# WHATPORT(5811)

## NAME

port 5811 — Unassigned — No IANA registration and no common service — an open 5811 is whatever local application claimed it.

Protocol: TCP  
IANA registry

## DESCRIPTION

5811 sits in a gap of the IANA registry: 5813 (icmpd) and 5814 (spt-automation) are registered, but 5811 is not, and no mainstream product defaults to it. Under VNC's 5800+display convention it would correspond to display :11, which is rare in practice. Treat a hit here as an unknown service and identify it directly.

## EXPOSURE

**Expose with care.** An unknown listener deserves no default trust. Confirm the process and its authentication before exposing it anywhere.

## CHECK

```sh
sudo lsof -nP -iTCP:5811 -sTCP:LISTEN
```

## SEE ALSO

- iana — [IANA port registry — 5811 (unassigned)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=5811) (iana.org)

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HTML: <https://whatport.net/5811/> · JSON: <https://whatport.net/5811.json> · full dataset: <https://whatport.net/ports.json>