# WHATPORT(9999)

## NAME

port 9999 — distinct / alternate HTTP — Registered as "distinct", but in practice the most common ad-hoc admin or alternate-HTTP port above 9000.

Protocol: TCP/UDP  
IANA registry

## DESCRIPTION

IANA registers 9999 as distinct, assigned to Distinct Corporation, with 9998 as distinct32 — a registration you will not meet in the field. What actually answers on 9999 is an HTTP service someone parked on a memorable number: Nmap's database labels it abyss, the Abyss Web Server's remote management console, and the port is a perennial favourite for debug endpoints, appliance UIs, and second web servers. At roughly 0.44% of scanned hosts, it is by far the busiest port in this range.

## EXPOSURE

**Expose with care.** Because it is almost always an ad-hoc HTTP surface rather than a standard protocol, assume it is a management interface until proven otherwise — and a management interface on a public IP is a never.

## CHECK

```sh
curl -sSI http://TARGET:9999/
```

## SEE ALSO

- iana — [IANA port registry — 9999 (distinct)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=9999) (iana.org)
- source — [nmap-services — Nmap's port frequency database](https://github.com/nmap/nmap/blob/master/nmap-services) (github.com)

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HTML: <https://whatport.net/9999/> · JSON: <https://whatport.net/9999.json> · full dataset: <https://whatport.net/ports.json>