Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2025-07-15
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
dhcpv6-client 546 udp DHCPv6 Client [IESG] [IETF_Chair] 2018-05-21 [RFC-ietf-dhc-rfc8415bis-12]
dhcpv6-server 547 tcp DHCPv6 Server [IESG] [IETF_Chair] 2018-05-21 [RFC5460]
dhcpv6-server 547 udp DHCPv6 Server [IESG] [IETF_Chair] 2018-05-21 [RFC-ietf-dhc-rfc8415bis-12]
afpovertcp 548 tcp AFP over TCP [Leland_Wallace] [Leland_Wallace] Defined TXT keys: u=<username> p=<password> path=<path>
afpovertcp 548 udp AFP over TCP [Leland_Wallace] [Leland_Wallace] Defined TXT keys: u=<username> p=<password> path=<path>
idfp 549 tcp IDFP [Ramana_Kovi] [Ramana_Kovi]
idfp 549 udp IDFP [Ramana_Kovi] [Ramana_Kovi]
new-rwho 550 tcp new-who [n/a]
new-rwho 550 udp new-who [n/a]
cybercash 551 tcp cybercash [Donald_E_Eastlake] [Donald_E_Eastlake] [RFC1898]
cybercash 551 udp cybercash [Donald_E_Eastlake] [Donald_E_Eastlake] [RFC1898]
devshr-nts 552 tcp DeviceShare [Benjamin_Rosenberg] [Benjamin_Rosenberg]
devshr-nts 552 udp DeviceShare [Benjamin_Rosenberg] [Benjamin_Rosenberg]
pirp 553 tcp pirp [D_J_Bernstein] [D_J_Bernstein]
pirp 553 udp pirp [D_J_Bernstein] [D_J_Bernstein]
rtsp 554 tcp Real Time Streaming Protocol (RTSP) [Rob_Lanphier] [Rob_Lanphier]
rtsp 554 udp Real Time Streaming Protocol (RTSP) [Rob_Lanphier] [Rob_Lanphier]
dsf 555 tcp
dsf 555 udp
remotefs 556 tcp rfs server
remotefs 556 udp rfs server
openvms-sysipc 557 tcp openvms-sysipc [Alan_Potter] [Alan_Potter]
openvms-sysipc 557 udp openvms-sysipc [Alan_Potter] [Alan_Potter]
sdnskmp 558 tcp SDNSKMP
sdnskmp 558 udp SDNSKMP
teedtap 559 tcp TEEDTAP [Charlie_Limoges] [Charlie_Limoges]
teedtap 559 udp TEEDTAP [Charlie_Limoges] [Charlie_Limoges]
rmonitor 560 tcp rmonitord
rmonitor 560 udp rmonitord
monitor 561 tcp
monitor 561 udp
chshell 562 tcp chcmd
chshell 562 udp chcmd
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]
9pfs 564 tcp plan 9 file service
9pfs 564 udp plan 9 file service
whoami 565 tcp whoami
whoami 565 udp whoami
streettalk 566 tcp streettalk
streettalk 566 udp streettalk
banyan-rpc 567 tcp banyan-rpc [Tom_Lemaire] [Tom_Lemaire]
banyan-rpc 567 udp banyan-rpc [Tom_Lemaire] [Tom_Lemaire]
ms-shuttle 568 tcp microsoft shuttle [Rudolph_Balaz] [Rudolph_Balaz]
ms-shuttle 568 udp microsoft shuttle [Rudolph_Balaz] [Rudolph_Balaz]
ms-rome 569 tcp microsoft rome [Rudolph_Balaz] [Rudolph_Balaz]
ms-rome 569 udp microsoft rome [Rudolph_Balaz] [Rudolph_Balaz]
meter 570 tcp demon
meter 570 udp demon
meter 571 tcp udemon
meter 571 udp udemon
sonar 572 tcp sonar [Keith_Moore] [Keith_Moore]
sonar 572 udp sonar [Keith_Moore] [Keith_Moore]
banyan-vip 573 tcp banyan-vip [Denis_Leclerc] [Denis_Leclerc]
banyan-vip 573 udp banyan-vip [Denis_Leclerc] [Denis_Leclerc]
ftp-agent 574 tcp FTP Software Agent System [Michael_S_Greenberg] [Michael_S_Greenberg]
ftp-agent 574 udp FTP Software Agent System [Michael_S_Greenberg] [Michael_S_Greenberg]
vemmi 575 tcp VEMMI [Daniel_Mavrakis_2] [Daniel_Mavrakis_2]
vemmi 575 udp VEMMI [Daniel_Mavrakis_2] [Daniel_Mavrakis_2]
ipcd 576 tcp ipcd
ipcd 576 udp ipcd
vnas 577 tcp vnas
vnas 577 udp vnas
ipdd 578 tcp ipdd [Jay_Farhat] [Jay_Farhat]
ipdd 578 udp ipdd [Jay_Farhat] [Jay_Farhat]
decbsrv 579 tcp decbsrv [Rudi_Martin] [Rudi_Martin]
decbsrv 579 udp decbsrv [Rudi_Martin] [Rudi_Martin]
sntp-heartbeat 580 tcp SNTP HEARTBEAT [Louis_Mamakos_2] [Louis_Mamakos_2]
sntp-heartbeat 580 udp SNTP HEARTBEAT [Louis_Mamakos_2] [Louis_Mamakos_2]
bdp 581 tcp Bundle Discovery Protocol [Gary_Malkin] [Gary_Malkin]
bdp 581 udp Bundle Discovery Protocol [Gary_Malkin] [Gary_Malkin]
scc-security 582 tcp SCC Security [Prashant_Dholakia] [Prashant_Dholakia]
scc-security 582 udp SCC Security [Prashant_Dholakia] [Prashant_Dholakia]
philips-vc 583 tcp Philips Video-Conferencing [Janna_Chang] [Janna_Chang]
philips-vc 583 udp Philips Video-Conferencing [Janna_Chang] [Janna_Chang]
keyserver 584 tcp Key Server [Gary_Howland] [Gary_Howland]
keyserver 584 udp Key Server [Gary_Howland] [Gary_Howland]
585 De-registered 2006-04-25 Use of 585 is not recommended, use 993 instead
password-chg 586 tcp Password Change
password-chg 586 udp Password Change
submission 587 tcp Message Submission 2011-11-17 [RFC6409]
submission 587 udp Message Submission 2011-11-17 [RFC6409]
cal 588 tcp CAL [Myron_Hattig] [Myron_Hattig]
cal 588 udp CAL [Myron_Hattig] [Myron_Hattig]
eyelink 589 tcp EyeLink [Dave_Stampe] [Dave_Stampe]
eyelink 589 udp EyeLink [Dave_Stampe] [Dave_Stampe]
tns-cml 590 tcp TNS CML [Jerome_Albin] [Jerome_Albin]
tns-cml 590 udp TNS CML [Jerome_Albin] [Jerome_Albin]
http-alt 591 tcp FileMaker, Inc. - HTTP Alternate (see Port 80) [Clay_Maeckel] [Clay_Maeckel]
http-alt 591 udp FileMaker, Inc. - HTTP Alternate (see Port 80) [Clay_Maeckel] [Clay_Maeckel]
eudora-set 592 tcp Eudora Set [Randall_Gellens] [Randall_Gellens]
eudora-set 592 udp Eudora Set [Randall_Gellens] [Randall_Gellens]
http-rpc-epmap 593 tcp HTTP RPC Ep Map [Edward_Reus] [Edward_Reus]
http-rpc-epmap 593 udp HTTP RPC Ep Map [Edward_Reus] [Edward_Reus]
tpip 594 tcp TPIP [Brad_Spear] [Brad_Spear]
tpip 594 udp TPIP [Brad_Spear] [Brad_Spear]
cab-protocol 595 tcp CAB Protocol [Winston_Hetherington] [Winston_Hetherington]
cab-protocol 595 udp CAB Protocol [Winston_Hetherington] [Winston_Hetherington]
smsd 596 tcp SMSD [Wayne_Barlow] [Wayne_Barlow]
smsd 596 udp SMSD [Wayne_Barlow] [Wayne_Barlow]
ptcnameservice 597 tcp PTC Name Service [Yuri_Machkasov] [Yuri_Machkasov]

Contact Information

ID Name Organization Contact URI Last Updated
[Alan_Potter] Alan Potter mailto:potter&movies.enet.dec.com
[Benjamin_Rosenberg] Benjamin Rosenberg mailto:brosenberg&advsyscon.com
[Brad_Spear] Brad Spear mailto:spear&platinum.com
[Charlie_Limoges] Charlie Limoges mailto:Charlie.Limoges&gdc4s.com
[Clay_Maeckel] Clay Maeckel mailto:clay&claris.com 2023-09-12
[D_J_Bernstein] D. J. Bernstein mailto:ports&box.cr.yp.to 2018-04-05
[Daniel_Mavrakis_2] Daniel Mavrakis mailto:mavrakis&mctel.fr
[Dave_Stampe] Dave Stampe mailto:dstampe&psych.toronto.edu
[Denis_Leclerc] Denis Leclerc mailto:DLeclerc&banyan.com
[Donald_E_Eastlake] Donald E. Eastlake 3rd mailto:d3e3e3&gmail.com
[Edward_Reus] Edward Reus mailto:edwardr&microsoft.com
[Gary_Howland] Gary Howland mailto:gary&systemics.com
[Gary_Malkin] Gary Malkin mailto:gmalkin&xylogics.com
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Janna_Chang] Janna Chang mailto:janna&pmc.philips.com
[Jay_Farhat] Jay Farhat mailto:jfarhat&ipass.com
[Jerome_Albin] Jerome Albin mailto:albin&taec.enet.dec.com
[Keith_Moore] Keith Moore mailto:moore&cs.utk.edu
[Leland_Wallace] Leland Wallace mailto:randall&apple.com
[Louis_Mamakos_2] Louis Mamakos mailto:louie&uu.net
[Michael_S_Greenberg] Michael S. Greenberg mailto:arnoff&ftp.com
[Myron_Hattig] Myron Hattig mailto:Myron_Hattig&ccm.jf.intel.com
[Prashant_Dholakia] Prashant Dholakia mailto:prashant&semaphorecom.com
[Ramana_Kovi] Ramana Kovi mailto:ramana&kovi.com
[Randall_Gellens] Randall Gellens mailto:rg+ietf&coretechnologyconsulting.com 2024-07-29
[Rob_Lanphier] Rob Lanphier mailto:robla&prognet.com
[Rudi_Martin] Rudi Martin mailto:movies::martin%22@movies.enet.dec.com
[Rudolph_Balaz] Rudolph Balaz mailto:rudolphb&microsoft.com
[Tom_Lemaire] Tom Lemaire mailto:toml&banyan.com
[Wayne_Barlow] Wayne Barlow mailto:web&unx.dec.com
[Winston_Hetherington] Winston Hetherington
[Yuri_Machkasov] Yuri Machkasov mailto:yuri&ptc.com