Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2025-03-11
Expert(s)
TCP/UDP: Joe Touch; Eliot Lear, Kumiko Ono, Wes Eddy, Brian Trammell, 
Jana Iyengar, 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
kpasswd 464 tcp kpasswd [Greg_Hudson_2] [Greg_Hudson_2] 2023-11-17
kpasswd 464 udp kpasswd [Greg_Hudson_2] [Greg_Hudson_2] 2023-11-17
nntps 563 tcp nntp protocol over TLS/SSL (was snntp) [IESG] [IETF_Chair] 2018-07-06 [RFC4642]
nntps 563 udp nntp protocol over TLS/SSL (was snntp) [IESG] [IETF_Chair] 2018-07-06 [RFC4642]
msl-lmd 1464 tcp MSL License Manager

IANA assigned this well-formed service name as a replacement for "msl_lmd".
[Matt_Timmermans] [Matt_Timmermans]
msl_lmd 1464 tcp MSL License Manager [Matt_Timmermans] [Matt_Timmermans] This entry is an alias to "msl-lmd". This entry is now historic, not usable for use with many common service discovery mechanisms.
msl-lmd 1464 udp MSL License Manager

IANA assigned this well-formed service name as a replacement for "msl_lmd".
[Matt_Timmermans] [Matt_Timmermans]
msl_lmd 1464 udp MSL License Manager [Matt_Timmermans] [Matt_Timmermans] This entry is an alias to "msl-lmd". This entry is now historic, not usable for use with many common service discovery mechanisms.
direcpc-si 2464 tcp DirecPC SI [Doug_Dillon] [Doug_Dillon]
direcpc-si 2464 udp DirecPC SI [Doug_Dillon] [Doug_Dillon]
edm-mgr-sync 3464 tcp EDM MGR Sync
edm-mgr-sync 3464 udp EDM MGR Sync
4622-4645 Unassigned
dots-signal 4646 tcp Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel. [IESG] [IETF_Chair] 2020-01-16 2021-06-14 [RFC8973][RFC9132]
dots-signal 4646 udp Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel. [IESG] [IETF_Chair] 2020-01-16 2021-06-14 [RFC8973][RFC9132]
4647-4657 Unassigned
quailnet 5464 tcp Quail Networks Object Broker [Craig_N_Bissell] [Craig_N_Bissell] 2006-04
quailnet 5464 udp Quail Networks Object Broker [Craig_N_Bissell] [Craig_N_Bissell] 2006-04
ieee11073-20701 6464 tcp Port assignment for medical device communication in accordance to IEEE 11073-20701 [David_Gregorczyk] [David_Gregorczyk] 2017-03-02
ieee11073-20701 6464 udp Port assignment for medical device communication in accordance to IEEE 11073-20701 [David_Gregorczyk] [David_Gregorczyk] 2017-03-02
18464-18515 Unassigned
24387-24464 Unassigned

Contact Information

ID Name Organization Contact URI Last Updated
[Craig_N_Bissell] Craig N. Bissell mailto:craig&quailnetworks.com 2006-04
[David_Gregorczyk] David Gregorczyk mailto:david.gregorczyk&draeger.com 2017-03-02
[Doug_Dillon] Doug Dillon mailto:dillon&hns.com
[Greg_Hudson_2] Greg Hudson mailto:ghudson&mit.edu 2023-11-17
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Matt_Timmermans] Matt Timmermans