Port 512 (exec, comsat, biff)

Document v1 · published by Koskamo · updated 2026-10-04

Port 512 is an IANA System Port assigned to exec, comsat, and biff over TCP and UDP.

Port: 512
Service exec: TCP — remote process execution; authentication performed using passwords and UNIX login names
Service comsat: UDP
Service biff: UDP — used by mail system to notify users of new mail received; currently receives messages only from processes on the same machine
Range: System Ports (0–1023)

Source and provenance

Original source: www.iana.org
Published on Koskamo by: Koskamo
Citation version: Document v1
Reuse: IANA Service Name and Transport Protocol Port Number Registry (iana.org/assignments/service-names-port-numbers), system ports 0-1023; registry data reproduced verbatim with references

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Version history

Published by Koskamo2026-10-04
Version 1