Service Name and Transport Protocol Port Number Registry

Last Updated
2026-09-02
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
47 tcp Reserved 2017-05-18 This entry has been removed on 2017-05-18.
47 udp Reserved 2017-05-18 This entry has been removed on 2017-05-18.
iso-ip 147 tcp ISO-IP [Marshall_Rose] [Marshall_Rose]
iso-ip 147 udp ISO-IP [Marshall_Rose] [Marshall_Rose]
subntbcst-tftp 247 tcp SUBNTBCST_TFTP

IANA assigned this well-formed service name as a replacement for "subntbcst_tftp".
[John_Fake] [John_Fake]
subntbcst_tftp 247 tcp SUBNTBCST_TFTP [John_Fake] [John_Fake] This entry is an alias to "subntbcst-tftp". This entry is now historic, not usable for use with many common service discovery mechanisms.
subntbcst-tftp 247 udp SUBNTBCST_TFTP

IANA assigned this well-formed service name as a replacement for "subntbcst_tftp".
[John_Fake] [John_Fake]
subntbcst_tftp 247 udp SUBNTBCST_TFTP [John_Fake] [John_Fake] This entry is an alias to "subntbcst-tftp". This entry is now historic, not usable for use with many common service discovery mechanisms.
fatserv 347 tcp Fatmen Server
fatserv 347 udp Fatmen Server
ddm-dfm 447 tcp DDM-Distributed File Management [Steven_Ritland] [Steven_Ritland]
ddm-dfm 447 udp DDM-Distributed File Management [Steven_Ritland] [Steven_Ritland]
scx-proxy 470 tcp scx-proxy [Scott_Narveson] [Scott_Narveson]
scx-proxy 470 udp scx-proxy [Scott_Narveson] [Scott_Narveson]
mondex 471 tcp Mondex [Bill_Reding] [Bill_Reding]
mondex 471 udp Mondex [Bill_Reding] [Bill_Reding]
ljk-login 472 tcp ljk-login [LJK] [LJK]
ljk-login 472 udp ljk-login [LJK] [LJK]
hybrid-pop 473 tcp hybrid-pop [Rami_Rubin] [Rami_Rubin]
hybrid-pop 473 udp hybrid-pop [Rami_Rubin] [Rami_Rubin]
tn-tl-w1 474 tcp tn-tl-w1
tn-tl-w2 474 udp tn-tl-w2 [Ed_Kress] [Ed_Kress]
tcpnethaspsrv 475 tcp tcpnethaspsrv [Michael_Zunke] [Michael_Zunke] 2010-07-23
tcpnethaspsrv 475 udp tcpnethaspsrv [Michael_Zunke] [Michael_Zunke] 2010-07-23
tn-tl-fd1 476 tcp tn-tl-fd1 [Ed_Kress] [Ed_Kress]
tn-tl-fd1 476 udp tn-tl-fd1 [Ed_Kress] [Ed_Kress]
ss7ns 477 tcp ss7ns [Jean_Michel_URSCH] [Jean_Michel_URSCH]
ss7ns 477 udp ss7ns [Jean_Michel_URSCH] [Jean_Michel_URSCH]
spsc 478 tcp spsc [Mike_Rieker] [Mike_Rieker]
spsc 478 udp spsc [Mike_Rieker] [Mike_Rieker]
iafserver 479 tcp iafserver
iafserver 479 udp iafserver
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 [RFC9915]
idxp 603 tcp IDXP [RFC4767]
idxp 603 udp IDXP [RFC4767]
dhcp-failover 647 tcp DHCP Failover [IESG] [IETF_Chair] 2018-05-21 [RFC8156]
dhcp-failover 647 udp DHCP Failover [Bernard_Volz] [Bernard_Volz]
fujitsu-dev 747 tcp Fujitsu Device Control
fujitsu-dev 747 udp Fujitsu Device Control
dhcp-failover2 847 tcp dhcp-failover 2 [Bernard_Volz] [Bernard_Volz]
dhcp-failover2 847 udp dhcp-failover 2 [Bernard_Volz] [Bernard_Volz]
gdoi 848 tcp GDOI [RFC3547]
gdoi 848 udp GDOI [RFC3547]
nas 991 tcp Netnews Administration System [Vera_Heinau][Heiko_Schlichting] [Vera_Heinau][Heiko_Schlichting] 2017-02-10 [RFC4707]
nas 991 udp Netnews Administration System [Vera_Heinau][Heiko_Schlichting] [Vera_Heinau][Heiko_Schlichting] 2017-02-10 [RFC4707]
exp1 1021 tcp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 udp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 sctp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 dccp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 tcp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 udp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 sctp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 dccp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
neod1 1047 tcp Sun's NEO Object Request Broker
neod1 1047 udp Sun's NEO Object Request Broker
capioverlan 1147 tcp CAPIoverLAN [Diego_Friedel] [Diego_Friedel] 2005-11
capioverlan 1147 udp CAPIoverLAN [Diego_Friedel] [Diego_Friedel] 2005-11
visionpyramid 1247 tcp VisionPyramid [Gavin_Hutchinson] [Gavin_Hutchinson]
visionpyramid 1247 udp VisionPyramid [Gavin_Hutchinson] [Gavin_Hutchinson]
bbn-mmc 1347 tcp multi media conferencing
bbn-mmc 1347 udp multi media conferencing
apri-lm 1447 tcp Applied Parallel Research LM [Jim_Dillon] [Jim_Dillon]
apri-lm 1447 udp Applied Parallel Research LM [Jim_Dillon] [Jim_Dillon]
uaiact 1470 tcp Universal Analytics [Mark_R_Ludwig] [Mark_R_Ludwig]
uaiact 1470 udp Universal Analytics [Mark_R_Ludwig] [Mark_R_Ludwig]
csdmbase 1471 tcp csdmbase
csdmbase 1471 udp csdmbase
csdm 1472 tcp csdm [Robert_Stabl] [Robert_Stabl]
csdm 1472 udp csdm [Robert_Stabl] [Robert_Stabl]
openmath 1473 tcp OpenMath [Garth_Mayville] [Garth_Mayville]
openmath 1473 udp OpenMath [Garth_Mayville] [Garth_Mayville]
telefinder 1474 tcp Telefinder [Jim_White] [Jim_White]
telefinder 1474 udp Telefinder [Jim_White] [Jim_White]
taligent-lm 1475 tcp Taligent License Manager [Mark_Sapsford] [Mark_Sapsford]
taligent-lm 1475 udp Taligent License Manager [Mark_Sapsford] [Mark_Sapsford]
clvm-cfg 1476 tcp clvm-cfg [Eric_Soderberg] [Eric_Soderberg]
clvm-cfg 1476 udp clvm-cfg [Eric_Soderberg] [Eric_Soderberg]
ms-sna-server 1477 tcp ms-sna-server
ms-sna-server 1477 udp ms-sna-server
ms-sna-base 1478 tcp ms-sna-base [Gordon_Mangione] [Gordon_Mangione]
ms-sna-base 1478 udp ms-sna-base [Gordon_Mangione] [Gordon_Mangione]
dberegister 1479 tcp dberegister [Brian_Griswold] [Brian_Griswold]
dberegister 1479 udp dberegister [Brian_Griswold] [Brian_Griswold]
laplink 1547 tcp laplink [Michael_Crawford] [Michael_Crawford]
laplink 1547 udp laplink [Michael_Crawford] [Michael_Crawford]
mil-2045-47001 1581 tcp MIL-2045-47001 [Eric_Whitehill] [Eric_Whitehill]
mil-2045-47001 1581 udp MIL-2045-47001 [Eric_Whitehill] [Eric_Whitehill]
rsap 1647 tcp rsap [Holger_Reif] [Holger_Reif]
rsap 1647 udp rsap [Holger_Reif] [Holger_Reif]
ftrapid-2 1747 tcp ftrapid-2 [Richard_J_Williams] [Richard_J_Williams]
ftrapid-2 1747 udp ftrapid-2 [Richard_J_Williams] [Richard_J_Williams]
slp-notify 1847 tcp SLP Notification [RFC3082]
slp-notify 1847 udp SLP Notification [RFC3082]
sentinelsrm 1947 tcp SentinelSRM [Michael_Zunke_2] [Michael_Zunke_2] 2010-07-23 Unauthorized Use Known on port 1947
sentinelsrm 1947 udp SentinelSRM [Michael_Zunke_2] [Michael_Zunke_2] 2010-07-23 Unauthorized Use Known on port 1947
dls 2047 tcp
dls 2047 udp
lv-auth 2147 tcp Live Vault Authentication [Ted_Hess] [Ted_Hess]
lv-auth 2147 udp Live Vault Authentication [Ted_Hess] [Ted_Hess]

Contact Information

ID Name Organization Contact URI Last Updated
[Bernard_Volz] Bernard Volz mailto:bevolz&gmail.com 2022-08-03
[Bill_Reding] Bill Reding mailto:redingb&nwdt.natwest.co.uk
[Brian_Griswold] Brian Griswold mailto:brian&dancingbear.com
[Diego_Friedel] Diego Friedel mailto:d.friedel&avm.de 2006-03
[Ed_Kress] Ed Kress mailto:eskress&thinknet.com
[Eric_Soderberg] Eric Soderberg mailto:seric&cup.hp.com
[Eric_Whitehill] Eric Whitehill mailto:Eric.Whitehill&itt.com
[Garth_Mayville] Garth Mayville mailto:mayville&maplesoft.on.ca
[Gavin_Hutchinson] Gavin Hutchinson mailto:gavinh&visionlogistics.com
[Gordon_Mangione] Gordon Mangione mailto:gordm&microsoft.com
[Heiko_Schlichting] Heiko Schlichting mailto:heiko.schlichting&fu-berlin.de 2022-06-07
[Holger_Reif] Holger Reif mailto:Holger.Reif&prakinf.tu-ilmenau.de
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Jean_Michel_URSCH] Jean-Michel URSCH mailto:ursch&taec.enet.dec.com
[Jim_Dillon] Jim Dillon mailto:jed&apri.com
[Jim_White] Jim White mailto:Jim_White&spiderisland.com
[John_Fake] John Fake mailto:fake&us.ibm.com
[LJK] LJK Software, Cambridge, Massachusetts mailto:support&ljk.com
[Mark_R_Ludwig] Mark R. Ludwig mailto:Mark-Ludwig&uai.com
[Mark_Sapsford] Mark Sapsford mailto:Mark_Sapsford&taligent.com
[Marshall_Rose] Marshall Rose mailto:mrose17&gmail.com 2024-07-29
[Michael_Crawford] Michael Crawford mailto:MichaelC&dev.travsoft.com
[Michael_Zunke] Michael Zunke mailto:michael.zunke&ealaddin.com 2010-07-23
[Michael_Zunke_2] Michael Zunke mailto:Michael.Zunke&ealaddin.com 2010-07-23
[Mike_Rieker] Mike Rieker mailto:mikea&sp32.com
[Rami_Rubin] Rami Rubin mailto:rami&hybrid.com
[Richard_J_Williams] Richard J. Williams mailto:RJW1&trpo4.tr.unisys.com
[Robert_Stabl] Robert Stabl mailto:stabl&informatik.uni-muenchen.de
[Scott_Narveson] Scott Narveson mailto:sjn&cray.com
[Steven_Ritland] Steven Ritland mailto:srr&us.ibm.com
[Ted_Hess] Ted Hess mailto:thess&livevault.com
[Vera_Heinau] Vera Heinau mailto:vera.heinau&fu-berlin.de 2022-06-07