---
name: "portmap"
section: "8"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["linux", "openbsd"]
url: "https://new.carta.tech/portmap"
---

# portmap(8)

Internet protocol port to RPC program number mapper

## NAME

**portmap** – Internet protocol port to RPC program number mapper

## SYNOPSIS

**portmap** \[**-d**\]

## DESCRIPTION

**portmap** is a server that converts RPC program numbers into Internet protocol port numbers. It must be running in order to make RPC calls.

When an RPC server is started, it will tell **portmap** what port number it is listening to, and what RPC program numbers it is prepared to serve. When a client wishes to make an RPC call to a given program number, it will first contact **portmap** on the server machine to determine the port number where RPC packets should be sent.

**portmap** must be started before any RPC servers are invoked.

Normally **portmap** forks and dissociates itself from the terminal like any other daemon. **portmap** then logs errors using [syslog(3)](/syslog/3.md).

The options are as follows:

- **-d**

  (debug) prevents **portmap** from running as a daemon, and causes errors and debugging information to be printed to the standard error output.

## SEE ALSO

[inetd(8)](/inetd/8.md), [rpcinfo(8)](/rpcinfo/8.md)

## HISTORY

The **portmap** command appeared in 4.3BSD.

## BUGS

If **portmap** crashes, all servers must be restarted.