Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2025-08-15
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
iasd 432 udp IASD [Nir_Baroz] [Nir_Baroz]
mobilip-mn 435 tcp MobilIP-MN [Kannan_Alagappan_2] [Kannan_Alagappan_2]
mobilip-mn 435 udp MobilIP-MN [Kannan_Alagappan_2] [Kannan_Alagappan_2]
cvc-hostd 442 tcp cvc_hostd

IANA assigned this well-formed service name as a replacement for "cvc_hostd".
[Bill_Davidson] [Bill_Davidson]
cvc_hostd 442 tcp cvc_hostd [Bill_Davidson] [Bill_Davidson] This entry is an alias to "cvc-hostd". This entry is now historic, not usable for use with many common service discovery mechanisms.
cvc-hostd 442 udp cvc_hostd

IANA assigned this well-formed service name as a replacement for "cvc_hostd".
[Bill_Davidson] [Bill_Davidson]
cvc_hostd 442 udp cvc_hostd [Bill_Davidson] [Bill_Davidson] This entry is an alias to "cvc-hostd". This entry is now historic, not usable for use with many common service discovery mechanisms.
https 443 sctp HTTPS [Randall_Stewart] [Randall_Stewart] 2022-02-07 [RFC9260]
sfs-config 452 tcp Cray SFS config server [Walter_Poxon] [Walter_Poxon]
sfs-config 452 udp Cray SFS config server [Walter_Poxon] [Walter_Poxon]
datasurfsrvsec 462 tcp DataRampSrvSec [Diane_Downie] [Diane_Downie]
datasurfsrvsec 462 udp DataRampSrvSec [Diane_Downie] [Diane_Downie]
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
photuris 468 tcp proturis [Bill_Simpson_2] [Bill_Simpson_2]
photuris 468 udp proturis [Bill_Simpson_2] [Bill_Simpson_2]
ljk-login 472 tcp ljk-login [LJK] [LJK]
ljk-login 472 udp ljk-login [LJK] [LJK]
tn-tl-w2 474 udp tn-tl-w2 [Ed_Kress] [Ed_Kress]
bgs-nsi 482 tcp bgs-nsi [Jon_Saperia] [Jon_Saperia]
bgs-nsi 482 udp bgs-nsi [Jon_Saperia] [Jon_Saperia]
avian 486 tcp avian [Robert_Ullmann_2] [Robert_Ullmann_2]
avian 486 udp avian [Robert_Ullmann_2] [Robert_Ullmann_2]
ticf-1 492 tcp Transport Independent Convergence for FNA
ticf-1 492 udp Transport Independent Convergence for FNA
ticf-2 493 tcp Transport Independent Convergence for FNA [Mamoru_Ito] [Mamoru_Ito]
ticf-2 493 udp Transport Independent Convergence for FNA [Mamoru_Ito] [Mamoru_Ito]
mbap 502 tcp Modbus Application Protocol [modbus.org] [Dennis_Dube] 2014-06-10
mbap 502 udp Modbus Application Protocol [modbus.org] [Dennis_Dube] 2014-06-10
exec 512 tcp remote process execution; authentication performed using passwords and UNIX login names
comsat 512 udp
biff 512 udp used by mail system to notify users of new mail received; currently receives messages only from processes on the same machine
syslog 514 udp 2020-06-01 [RFC5426]
efs 520 tcp extended file name server
router 520 udp local routing process (on site); uses variant of Xerox NS routing information protocol - RIP
ripng 521 tcp ripng [Robert_E_Minnear] [Robert_E_Minnear]
ripng 521 udp ripng [Robert_E_Minnear] [Robert_E_Minnear]
ulp 522 tcp ULP [Max_Morris] [Max_Morris]
ulp 522 udp ULP [Max_Morris] [Max_Morris]
ibm-db2 523 tcp IBM-DB2 [Juliana_Hsu] [Juliana_Hsu]
ibm-db2 523 udp IBM-DB2 [Juliana_Hsu] [Juliana_Hsu]
ncp 524 tcp NCP [Don_Provan_2] [Don_Provan_2]
ncp 524 udp NCP [Don_Provan_2] [Don_Provan_2]
timed 525 tcp timeserver
timed 525 udp timeserver
tempo 526 tcp newdate
tempo 526 udp newdate
stx 527 tcp Stock IXChange [Ferdi_Ladeira] [Ferdi_Ladeira] 2022-01-25
stx 527 udp Stock IXChange [Ferdi_Ladeira] [Ferdi_Ladeira] 2022-01-25
custix 528 tcp Customer IXChange [Ferdi_Ladeira] [Ferdi_Ladeira] 2022-01-25
custix 528 udp Customer IXChange [Ferdi_Ladeira] [Ferdi_Ladeira] 2022-01-25
irc-serv 529 tcp IRC-SERV [Brian_Tackett] [Brian_Tackett]
irc-serv 529 udp IRC-SERV [Brian_Tackett] [Brian_Tackett]
netnews 532 tcp readnews
netnews 532 udp readnews
commerce 542 tcp commerce [Randy_Epstein] [Randy_Epstein]
commerce 542 udp commerce [Randy_Epstein] [Randy_Epstein]
dhcpv6-client 546 udp DHCPv6 Client [IESG] [IETF_Chair] 2018-05-21 [RFC-ietf-dhc-rfc8415bis-12]
dhcpv6-server 547 udp DHCPv6 Server [IESG] [IETF_Chair] 2018-05-21 [RFC-ietf-dhc-rfc8415bis-12]
devshr-nts 552 tcp DeviceShare [Benjamin_Rosenberg] [Benjamin_Rosenberg]
devshr-nts 552 udp DeviceShare [Benjamin_Rosenberg] [Benjamin_Rosenberg]
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]
sonar 572 tcp sonar [Keith_Moore] [Keith_Moore]
sonar 572 udp sonar [Keith_Moore] [Keith_Moore]
vemmi 575 tcp VEMMI [Daniel_Mavrakis_2] [Daniel_Mavrakis_2]
vemmi 575 udp VEMMI [Daniel_Mavrakis_2] [Daniel_Mavrakis_2]
sntp-heartbeat 580 tcp SNTP HEARTBEAT [Louis_Mamakos_2] [Louis_Mamakos_2]
sntp-heartbeat 580 udp SNTP HEARTBEAT [Louis_Mamakos_2] [Louis_Mamakos_2]
scc-security 582 tcp SCC Security [Prashant_Dholakia] [Prashant_Dholakia]
scc-security 582 udp SCC Security [Prashant_Dholakia] [Prashant_Dholakia]
eudora-set 592 tcp Eudora Set [Randall_Gellens] [Randall_Gellens]
eudora-set 592 udp Eudora Set [Randall_Gellens] [Randall_Gellens]
xmlrpc-beep 602 tcp XML-RPC over BEEP [RFC3529]
xmlrpc-beep 602 udp XML-RPC over BEEP [RFC3529]
tunnel 604 tcp TUNNEL [RFC3620]
tunnel 604 udp TUNNEL [RFC3620]
soap-beep 605 tcp SOAP over BEEP [RFC4227]
soap-beep 605 udp SOAP over BEEP [RFC4227]
hmmp-ind 612 tcp HMMP Indication
hmmp-ind 612 udp HMMP Indication
sco-websrvrmgr 620 tcp SCO WebServer Manager [Christopher_Durham] [Christopher_Durham]
sco-websrvrmgr 620 udp SCO WebServer Manager [Christopher_Durham] [Christopher_Durham]
escp-ip 621 tcp ESCP [Lai_Zit_Seng] [Lai_Zit_Seng]
escp-ip 621 udp ESCP [Lai_Zit_Seng] [Lai_Zit_Seng]
collaborator 622 tcp Collaborator [Johnson_Davis] [Johnson_Davis]
collaborator 622 udp Collaborator [Johnson_Davis] [Johnson_Davis]
oob-ws-http 623 tcp DMTF out-of-band web services management protocol [Jim_Davis] [Jim_Davis] 2007-06
asf-rmcp 623 udp ASF Remote Management and Control Protocol [Carl_First] [Carl_First]
cryptoadmin 624 tcp Crypto Admin [Tony_Walker] [Tony_Walker]
cryptoadmin 624 udp Crypto Admin [Tony_Walker] [Tony_Walker]
dec-dlm 625 tcp DEC DLM

IANA assigned this well-formed service name as a replacement for "dec_dlm".
[Rudi_Martin_2] [Rudi_Martin_2]
dec_dlm 625 tcp DEC DLM [Rudi_Martin_2] [Rudi_Martin_2] This entry is an alias to "dec-dlm". This entry is now historic, not usable for use with many common service discovery mechanisms.
dec-dlm 625 udp DEC DLM

IANA assigned this well-formed service name as a replacement for "dec_dlm".
[Rudi_Martin_2] [Rudi_Martin_2]
dec_dlm 625 udp DEC DLM [Rudi_Martin_2] [Rudi_Martin_2] This entry is an alias to "dec-dlm". This entry is now historic, not usable for use with many common service discovery mechanisms.
asia 626 tcp ASIA [Michael_Dasenbrock] [Michael_Dasenbrock]
asia 626 udp ASIA [Michael_Dasenbrock] [Michael_Dasenbrock]
passgo-tivoli 627 tcp PassGo Tivoli [John_Rainford_2] [John_Rainford_2]
passgo-tivoli 627 udp PassGo Tivoli [John_Rainford_2] [John_Rainford_2]

Contact Information

ID Name Organization Contact URI Last Updated
[Benjamin_Rosenberg] Benjamin Rosenberg mailto:brosenberg&advsyscon.com
[Bill_Davidson] Bill Davidson mailto:billd&equalizer.cray.com
[Bill_Simpson_2] Bill Simpson mailto:Bill.Simpson&um.cc.umich.edu
[Brian_Tackett] Brian Tackett mailto:cym&acrux.net
[Carl_First] Carl First mailto:Carl.L.First&intel.com
[Christopher_Durham] Christopher Durham mailto:chrisdu&sco.com
[Daniel_Mavrakis_2] Daniel Mavrakis mailto:mavrakis&mctel.fr
[Dennis_Dube] Dennis Dube mailto:dennis.dube&schneider-electric.com 2014-06-10
[Diane_Downie] Diane Downie mailto:downie&jibe.mv.com
[Don_Provan_2] Don Provan mailto:donp&sjf.novell.com
[Ed_Kress] Ed Kress mailto:eskress&thinknet.com
[Ferdi_Ladeira] Ferdi Ladeira mailto:f.lad.mail&gmail.com 2022-01-25
[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
[Jim_Davis] Jim Davis mailto:jim.davis&wbemsolutions.com 2007-06
[John_Rainford_2] John Rainford mailto:john.rainford&passgo.com
[Johnson_Davis] Johnson Davis mailto:johnsond&opteamasoft.com
[Jon_Saperia] Jon Saperia mailto:saperia&bgs.com
[Juliana_Hsu] Juliana Hsu mailto:jhsu&ca.ibm.com
[Kannan_Alagappan_2] Kannan Alagappan mailto:kannan&sejour.lkg.dec.com
[Keith_Moore] Keith Moore mailto:moore&cs.utk.edu
[LJK] LJK Software, Cambridge, Massachusetts mailto:support&ljk.com
[Lai_Zit_Seng] Lai Zit Seng mailto:lzs&pobox.com
[Louis_Mamakos_2] Louis Mamakos mailto:louie&uu.net
[Mamoru_Ito] Mamoru Ito mailto:Ito&pcnet.ks.pfu.co.jp
[Max_Morris] Max Morris mailto:maxm&microsoft.com
[Michael_Dasenbrock] Michael Dasenbrock mailto:dasenbro&apple.com
[modbus.org] modbus.org mailto:rbelliardi&modbus.org 2014-06-10
[Nir_Baroz] Nir Baroz mailto:nbaroz&encore.com
[Prashant_Dholakia] Prashant Dholakia mailto:prashant&semaphorecom.com
[Randall_Gellens] Randall Gellens mailto:rg+ietf&coretechnologyconsulting.com 2024-07-29
[Randall_Stewart] Randall Stewart IETF TSVWG mailto:rrs&lakerest.net
[Randy_Epstein] Randy Epstein mailto:randy&epstein.com 2023-10-18
[Robert_E_Minnear] Robert E. Minnear mailto:minnear&ipsilon.com
[Robert_Ullmann_2] Robert Ullmann mailto:Robert_Ullmann/CAM/Lotus.LOTUS@crd.lotus.com
[Rudi_Martin_2] Rudi Martin mailto:Rudi.Martin&edo.mts.dec.com
[Tony_Walker] Tony Walker mailto:tony&cryptocard.com
[Walter_Poxon] Walter Poxon mailto:wdp&ironwood.cray.com