---
name: "mopd"
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/mopd"
---

# mopd(8)

MOP loader daemon

## NAME

**mopd** – MOP loader daemon

## SYNOPSIS

**mopd** \[**-3** \| **-4**\] \[**-adfv**\] *interface*

## DESCRIPTION

**mopd** services MOP Load requests on the Ethernet connected to *interface* or all interfaces if **-a** is given. In a load request received by **mopd** a filename can be given. This is the normal case for, e.g., terminal servers. If a filename isn't given, **mopd** must know what image to load.

Upon receiving a request, **mopd** checks if the requested file exists in */tftpboot/mop*. The filename is normally all uppercase and with an extension of *.SYS*. If the filename isn't given, the Ethernet address of the target is used as filename (e.g., *08002b09f4de.SYS*), and it might be a soft link to another file.

**mopd** supports two kinds of files. The file is first checked to see if it is in a.out format. If not, a few of Digital's formats are checked.

In normal operation, **mopd** forks a copy of itself and runs in the background. Anomalies and errors are reported via [syslog(3)](/syslog/3.md).

The options are as follows:

- **-3**

  Ignore MOP V3 messages (Ethernet II).

- **-4**

  Ignore MOP V4 messages (Ethernet 802.3).

- **-a**

  Listen on all the Ethernets attached to the system. If **-a** is omitted, an interface must be specified.

- **-d**

  Run in debug mode, with all the output to stdout. The process will run in the foreground.

- **-f**

  Run in the foreground.

- **-v**

  Show version of **mopd**.

## FILES

- */tftpboot/mop*

  ## SEE ALSO

[mopa.out(1)](/mopa.out/1.md), [mopchk(1)](/mopchk/1.md), [mopprobe(1)](/mopprobe/1.md), [moptrace(1)](/moptrace/1.md), [bpf(4)](/bpf/4.md) *DECnet Digital Network Architecture Phase IV*, Maintenance Operations Functional Specification V3.0.0, AA-X436A-TK. *DECnet Digital Network Architecture*, Maintenance Operations Protocol Functional Specification V4.0.0, EK-DNA11-FS-001.

## AUTHORS

Mats O Jansson ⟨*moj@stacken.kth.se*⟩

## BUGS

a.out isn't supported yet on non-BSD implementations (otherOS).