# WHATPORT(1024)

## NAME

port 1024 — Reserved — first port above the privileged range — IANA-reserved, and the boundary: the lowest port an unprivileged process can bind.

Protocol: TCP  
IANA registry

## DESCRIPTION

RFC 6335 puts 1024–49151 in the User (registered) range, and IANA holds 1024 itself Reserved, so nothing standard is assigned to it. Its real significance is structural — it is the first port a non-root process may bind on a Unix-like system, and older Windows releases (2000, XP, Server 2003) started their dynamic client-port allocation at the low end of 1025–5000, with Vista and Server 2008 moving to 49152–65535. nmap labels 1024 kdm, after KDE's display manager, which is a historical guess rather than a live protocol.

## EXPOSURE

**Expose with care.** Anything listening here is unprivileged and locally chosen. That is not automatically dangerous, but it is unidentified until you look, and firewall rules written around the 1024 boundary are about privilege, not trust.

## CHECK

```sh
sudo lsof -nP -iTCP:1024 -sTCP:LISTEN
```

## SEE ALSO

- spec — [RFC 6335 — Port ranges: System (0–1023), User, and Dynamic](https://www.rfc-editor.org/rfc/rfc6335.html) (rfc-editor.org)
- docs — [Microsoft — Service overview and network port requirements (default dynamic port ranges)](https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/service-overview-and-network-port-requirements) (learn.microsoft.com)
- iana — [IANA Service Name and Transport Protocol Port Number Registry (1024 Reserved)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml) (iana.org)

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HTML: <https://whatport.net/1024/> · JSON: <https://whatport.net/1024.json> · full dataset: <https://whatport.net/ports.json>