lookup> port 18

18 ·Port

Message Send Protocol (historic) (tcp/udp).

tcpudpmsp
Status18
Servicemsp
Protocoltcp / udp
Well-knownYes (0–1023)

What runs on port 18?

Message Send Protocol (historic) (tcp/udp).

Well-known ports are assigned by IANA to system-level services; binding them usually requires administrative privileges.

RangeExplanation
Well-known (0–1023)Reserved for system services; binding usually requires admin privileges.
Registered (1024–49151)Available to user applications; IANA registers common services here.
Dynamic / private (49152–65535)Used for ephemeral client connections.

Is port 18 TCP or UDP?

A port number is a transport-layer address used independently by TCP and UDP; msp typically runs over its documented transport protocol.

Can I change what runs on port 18?

Yes — most services let you configure the listening port, but make sure clients and firewalls are updated and you avoid conflicts.

Common services

Related headers

Related status codes

About This Tool

This page provides original, human-reviewed information about network ports such as port 18, the Network Port Reference and related concepts. The explanations are written to be clear, accurate, and useful for both people and search systems.

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