# WHATPORT(1999)

## NAME

port 1999 — Cisco identification port — Registered to Cisco as an identification port; rarely seen in the wild.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA lists 1999 as tcp-id-port, "cisco identification port", registered by Cisco Systems. There is no public protocol specification for it and it is not a service you deliberately turn on. In practice a listener here is either a Cisco device or, more often, an unrelated application that grabbed a round number just below 2000.

## EXPOSURE

**Expose with care.** Nothing well documented runs here, so treat an open 1999 as an unidentified listener: fingerprint it before deciding, and do not expose an unknown service to the internet.

## CHECK

```sh
nc -vz TARGET 1999
```

## SEE ALSO

- iana — [IANA port registry — 1999 (tcp-id-port)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=1999) (iana.org)

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HTML: <https://whatport.net/1999/> · JSON: <https://whatport.net/1999.json> · full dataset: <https://whatport.net/ports.json>