Service Name and Transport Protocol Port Number Registry

Last Updated
2026-09-30
Expert(s)
TCP/UDP: Joe Touch; Eliot Lear, Kumiko Ono, Wes Eddy, Brian Trammell,
and Michael Scharf
SCTP: Michael Tuexen
DCCP: Eddie Kohler and Yoshifumi Nishida
Reference
[RFC 6335]
Note
Service names and port numbers are used to distinguish between different
services that run over transport protocols such as TCP, UDP, DCCP, and
SCTP.

Service names are assigned on a first-come, first-served process, as
documented in [RFC 6335].

Port numbers are assigned in various ways, based on three ranges: System
Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private
Ports (49152-65535); the different uses of these ranges are described in
[RFC 6335]. According to Section 8.1.2 of [RFC 6335], System Ports are 
assigned by the "IETF Review" or "IESG Approval" procedures described in 
[RFC 8126]. User Ports are assigned by IANA using the "IETF Review" process, 
the "IESG Approval" process, or the "Expert Review" process, as per 
[RFC 6335]. Dynamic Ports are not assigned.

The registration procedures for service names and port numbers are
described in [RFC 6335].

Assigned ports both System and User ports SHOULD NOT be used without
or prior to IANA registration.

************************************************************************
* PLEASE NOTE THE FOLLOWING:                                           *
*                                                                      *
* ASSIGNMENT OF A PORT NUMBER DOES NOT IN ANY WAY IMPLY AN             *
* ENDORSEMENT OF AN APPLICATION OR PRODUCT, AND THE FACT THAT NETWORK  *
* TRAFFIC IS FLOWING TO OR FROM A REGISTERED PORT DOES NOT MEAN THAT   *
* IT IS "GOOD" TRAFFIC, NOR THAT IT NECESSARILY CORRESPONDS TO THE     *
* ASSIGNED SERVICE. FIREWALL AND SYSTEM ADMINISTRATORS SHOULD          *
* CHOOSE HOW TO CONFIGURE THEIR SYSTEMS BASED ON THEIR KNOWLEDGE OF    *
* THE TRAFFIC IN QUESTION, NOT WHETHER THERE IS A PORT NUMBER          *
* REGISTERED OR NOT.                                                   *
************************************************************************

Request an Assignment
  [https://www.iana.org/protocols/apply]

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TXT
Service Name Port Number Transport Protocol Description Assignee Contact Registration Date Modification Date Reference Service Code Unauthorized Use Reported Assignment Notes
login 513 tcp remote login a la telnet; automatic authentication performed based on priviledged port numbers and distributed data bases which identify "authentication domains"
who 513 udp maintains data bases showing who's logged in to machines on a local net and the load average of the machine
fujitsu-dtc 1513 tcp Fujitsu Systems Business of America, Inc
fujitsu-dtc 1513 udp Fujitsu Systems Business of America, Inc
citrixadmin 2513 tcp Citrix ADMIN [Myk_Willis] [Myk_Willis]
citrixadmin 2513 udp Citrix ADMIN [Myk_Willis] [Myk_Willis]
mdtp 3232 tcp MDT port 2012-02-21 [RFC 6513]
mdtp 3232 udp MDT port 2012-02-21 [RFC 6513]
arcpd 3513 tcp Adaptec Remote Protocol [Hardy_Doelfel] [Hardy_Doelfel] 2002-05
arcpd 3513 udp Adaptec Remote Protocol [Hardy_Doelfel] [Hardy_Doelfel] 2002-05
5121-5132 Unassigned
nbt-pc 5133 tcp Policy Commander [Emily_Harris] [Emily_Harris] 2004-11
nbt-pc 5133 udp Policy Commander [Emily_Harris] [Emily_Harris] 2004-11
ppactivation 5134 tcp PP ActivationServer [Ian_Bradley] [Ian_Bradley] 2009-10-14
5134 udp Reserved
erp-scale 5135 tcp ERP-Scale [Ian_Bradley] [Ian_Bradley] 2009-10-14 Defined TXT keys:
RFC=<RFC destination and status>
Device=<Scale device and status>
5135 udp Reserved
5136 tcp Reserved
minotaur-sa 5136 udp Minotaur SA [Kenneth_Flynn] [Kenneth_Flynn] 2009-10-14
ctsd 5137 tcp MyCTS server port [Jilles_Oldenbeuving] [Jilles_Oldenbeuving] 2002-06
ctsd 5137 udp MyCTS server port [Jilles_Oldenbeuving] [Jilles_Oldenbeuving] 2002-06
5138-5144 Unassigned
netconf-tls 6513 tcp NETCONF over TLS [IESG] [IETF_Chair] 2024-01-24 [RFC 7589][RFC 9918]
6513 udp Reserved
45186-45513 Unassigned

Contact Information

ID Name Organization Contact URI Last Updated
[Emily_Harris] Emily Harris mailto:eharris&newboundary.com 2004-11
[Hardy_Doelfel] Hardy Doelfel mailto:hardy_doelfel&adaptec.com 2002-05
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Ian_Bradley] Ian Bradley mailto:ian.bradley&pocketprograms.com
mailto:development&pocketprograms.com
2009-10-14
[Jilles_Oldenbeuving] Jilles Oldenbeuving mailto:ojilles&gmail.com 2020-11-18
[Kenneth_Flynn] Kenneth Flynn mailto:flynnk&darkcornersoftware.com 2009-10-14
[Myk_Willis] Myk Willis mailto:myk.willis&citrix.com