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
personal-link 281 tcp Personal Link [Dan_Cummings] [Dan_Cummings]
personal-link 281 udp Personal Link [Dan_Cummings] [Dan_Cummings]
healthd 1281 tcp healthd [James_E_Housley] [James_E_Housley]
healthd 1281 udp healthd [James_E_Housley] [James_E_Housley]
hsrp 1985 tcp Hot Standby Router Protocol [RFC2281]
hsrp 1985 udp Hot Standby Router Protocol [RFC2281]
lnvconsole 2281 tcp LNVCONSOLE
lnvconsole 2281 udp LNVCONSOLE
netsteward 2810 tcp Active Net Steward [Keith_Morley] [Keith_Morley]
netsteward 2810 udp Active Net Steward [Keith_Morley] [Keith_Morley]
gsiftp 2811 tcp GSI FTP [Von_Welch] [Von_Welch]
gsiftp 2811 udp GSI FTP [Von_Welch] [Von_Welch]
atmtcp 2812 tcp atmtcp [Werner_Almesberger] [Werner_Almesberger]
atmtcp 2812 udp atmtcp [Werner_Almesberger] [Werner_Almesberger]
llm-pass 2813 tcp llm-pass [Loftware] [Glen_Sansoucie] 2020-07-20
llm-pass 2813 udp llm-pass [Loftware] [Glen_Sansoucie] 2020-07-20
llm-csv 2814 tcp llm-csv [Loftware] [Glen_Sansoucie] 2020-07-20
llm-csv 2814 udp llm-csv [Loftware] [Glen_Sansoucie] 2020-07-20
lbc-measure 2815 tcp LBC Measurement
lbc-measure 2815 udp LBC Measurement
lbc-watchdog 2816 tcp LBC Watchdog [Akiyoshi_Ochi] [Akiyoshi_Ochi]
lbc-watchdog 2816 udp LBC Watchdog [Akiyoshi_Ochi] [Akiyoshi_Ochi]
nmsigport 2817 tcp NMSig Port [Peter_Egli_2] [Peter_Egli_2]
nmsigport 2817 udp NMSig Port [Peter_Egli_2] [Peter_Egli_2]
rmlnk 2818 tcp rmlnk
rmlnk 2818 udp rmlnk
fc-faultnotify 2819 tcp FC Fault Notification [Dave_Watkins] [Dave_Watkins]
fc-faultnotify 2819 udp FC Fault Notification [Dave_Watkins] [Dave_Watkins]
sysopt 3281 tcp SYSOPT [Tony_Hoffman] [Tony_Hoffman]
sysopt 3281 udp SYSOPT [Tony_Hoffman] [Tony_Hoffman]
undo-lm 5281 tcp Undo License Manager [Undo_Ltd] [Edward_Moffett] 2010-04-19 2019-01-25
5281 udp Reserved
itactionserver2 7281 tcp ITACTIONSERVER 2 [Brian_Taylor] [Brian_Taylor]
itactionserver2 7281 udp ITACTIONSERVER 2 [Brian_Taylor] [Brian_Taylor]
8281 Unassigned
swtp-port1 9281 tcp SofaWare transport port 1 [Amir_Rapson] [Amir_Rapson] 2002-02
swtp-port1 9281 udp SofaWare transport port 1 [Amir_Rapson] [Amir_Rapson] 2002-02
28081-28118 Unassigned
28119 tcp Reserved
a27-ran-ran 28119 udp A27 cdma2000 RAN Management [_3GPP_2] [Zhiming_Li] 2012-04-13
28120-28199 Unassigned
32802-32810 Unassigned
retp 32811 tcp Real Estate Transport Protocol [Corey_Leong] [Corey_Leong] 2010-10-11
32811 udp Reserved
32812-32895 Unassigned
autotunnel udp IPSEC VPN tunnel over UDP [Stuart_Cheshire] [Stuart_Cheshire] 2019-05-04 [RFC6281] Defined TXT Keys: None
dns-llq-tls tcp DNS Long-Lived Queries over TLS [Stuart_Cheshire] [Stuart_Cheshire] 2019-05-04 [RFC6281] Defined TXT Keys: None
dns-update-tls tcp DNS Dynamic Update Service over TLS [Stuart_Cheshire] [Stuart_Cheshire] 2019-05-04 [RFC6281] DNS Dynamic Update Service for a given domain may not necessarily be provided by the principal name servers as advertised by the domain's "NS" records, and may not necessarily always be provided on port 53. The "_dns-update._udp.<domain>." SRV record gives the target host and port where DNS Dynamic Update Service is provided for the named domain.

Contact Information

ID Name Organization Contact URI Last Updated
[_3GPP_2] 3GPP2 mailto:lizhiming&huawei.com 2012-01-11
[Akiyoshi_Ochi] Akiyoshi Ochi mailto:akiyoshi&net.paso.fujitsu.co.jp
[Amir_Rapson] Amir Rapson mailto:rapson&sofaware.com 2002-02
[Brian_Taylor] Brian Taylor mailto:btaylor&imagetag.com
[Corey_Leong] Corey Leong mailto:cleong&gr8c.org 2010-10-11
[Dan_Cummings] Dan Cummings mailto:doc&cnr.com
[Dave_Watkins] Dave Watkins mailto:davew&boi.hp.com
[Edward_Moffett] Edward Moffett Undo Ltd mailto:office.manager&undo.io 2019-01-25
[Glen_Sansoucie] Glen Sansoucie Loftware mailto:gsansoucie&loftware.com 2020-07-20
[James_E_Housley] James E. Housley mailto:jim&thehousleys.net
[Keith_Morley] Keith Morley mailto:keith&ndl.co.uk
[Loftware] Loftware mailto:gsansoucie&loftware.com 2020-07-20
[Peter_Egli_2] Peter Egli mailto:peter.egli&mail.inalp.com
[Stuart_Cheshire] Stuart Cheshire mailto:cheshire&apple.com 2022-07-11
[Tony_Hoffman] Tony Hoffman mailto:ajh&unx.dec.com
[Undo_Ltd] Undo Ltd mailto:office.manager&undo.io 2019-01-25
[Von_Welch] Von Welch mailto:vwelch&ncsa.uiuc.edu
[Werner_Almesberger] Werner Almesberger mailto:Werner.Almesberger&epfl.ch
[Zhiming_Li] Zhiming Li 3GPP2 mailto:lizhiming&huawei.com 2012-01-11