Service Name and Transport Protocol Port Number Registry

Last Updated
2026-08-17
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
[RFC6335]
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 [RFC6335].

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
[RFC6335]. According to Section 8.1.2 of [RFC6335], System Ports are 
assigned by the "IETF Review" or "IESG Approval" procedures described in 
[RFC8126]. User Ports are assigned by IANA using the "IETF Review" process, 
the "IESG Approval" process, or the "Expert Review" process, as per 
[RFC6335]. Dynamic Ports are not assigned.

The registration procedures for service names and port numbers are
described in [RFC6335].

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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Service Name Port Number Transport Protocol Description Assignee Contact Registration Date Modification Date Reference Service Code Unauthorized Use Reported Assignment Notes
pim-rp-disc 496 tcp PIM-RP-DISC [Dino_Farinacci] [Dino_Farinacci]
pim-rp-disc 496 udp PIM-RP-DISC [Dino_Farinacci] [Dino_Farinacci]
liberty-lm 1496 tcp liberty-lm [Jim_Rogers] [Jim_Rogers]
liberty-lm 1496 udp liberty-lm [Jim_Rogers] [Jim_Rogers]
dirgis 2496 tcp DIRGIS [Deutschland_Informat] [Deutschland_Informat]
dirgis 2496 udp DIRGIS [Deutschland_Informat] [Deutschland_Informat]
seclayer-tls 3496 tcp securitylayer over tls [Arno_Hollosi] [Arno_Hollosi] 2002-03
seclayer-tls 3496 udp securitylayer over tls [Arno_Hollosi] [Arno_Hollosi] 2002-03
4954-4968 Unassigned Known UNAUTHORIZED USE: port 4967
ccss-qmm 4969 tcp CCSS QMessageMonitor
ccss-qmm 4969 udp CCSS QMessageMonitor
34568-34961 Unassigned
profinet-rt 34962 tcp PROFInet RT Unicast [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2004-11 2026-03-16
profinet-rt 34962 udp PROFInet RT Unicast [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2004-11 2026-03-16
profinet-rtm 34963 tcp PROFInet RT Multicast [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2004-11 2026-03-16
profinet-rtm 34963 udp PROFInet RT Multicast [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2004-11 2026-03-16
profinet-cm 34964 tcp PROFInet Context Manager [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2004-11 2026-03-16
profinet-cm 34964 udp PROFInet Context Manager [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2004-11 2026-03-16
profinet-cm-sec 34965 tcp PROFINET secure connection management and key provisioning [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2026-03-10
profinet-cm-sec 34965 udp PROFINET secure connection management and key provisioning [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2026-03-10
34966 tcp Reserved
profinet-rt-sec 34966 udp PROFINET secure real-time data transfer over UDP (unicast and multicast) [PNO_PROFIBUS_Nutzerorganisation_e.V.] [Dietmar_Bohn] 2026-03-10
34967-34979 Unassigned

Contact Information

ID Name Contact URI Last Updated
[Arno_Hollosi] Arno Hollosi mailto:arno.hollosi&cio.gv.at 2002-03
[Deutschland_Informat] Deutschland Informations und Reservierungsgesellschaft mbH mailto:beratung&dirg.de
[Dietmar_Bohn] Dietmar Bohn mailto:standards.central-office&profibus.com 2026-03-10
[Dino_Farinacci] Dino Farinacci mailto:dino&cisco.com 2008-08-21
[Jim_Rogers] Jim Rogers mailto:trane!jimbo&pacbell.com
[PNO_PROFIBUS_Nutzerorganisation_e.V.] PNO – PROFIBUS Nutzerorganisation e.V. mailto:standards.central-office&profibus.com 2026-03-10