# WHATPORT(340)

## NAME

port 340 — Unassigned — Unassigned in the IANA registry, with no protocol or product convention behind it.

Protocol: TCP  
IANA registry

## DESCRIPTION

There is no IANA entry for 340 on either transport; the block from 334 through 343 is empty. Nmap records it as "unknown" on both TCP and UDP with a small open rate, meaning some hosts do answer but no consistent service explains them. Nothing about the number implies a protocol, an encoding, or an authentication model. Probe the listener and identify it on its own evidence.

## EXPOSURE

**Expose with care.** Unregistered and unidentified — nothing here justifies internet exposure until you know what process is bound to it.

## CHECK

```sh
nmap -sV -p 340 TARGET
```

## SEE ALSO

- iana — [IANA Service Name and Transport Protocol Port Number Registry — 340](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=340) (iana.org)

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HTML: <https://whatport.net/340/> · JSON: <https://whatport.net/340.json> · full dataset: <https://whatport.net/ports.json>