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
td-replica 268 tcp Tobit David Replica [Franz_Josef_Leuders] [Franz_Josef_Leuders]
td-replica 268 udp Tobit David Replica [Franz_Josef_Leuders] [Franz_Josef_Leuders]
manet 269 tcp MANET Protocols [RFC5498]
manet 269 udp MANET Protocols [RFC5498]
270 tcp Reserved
gist 270 udp Q-mode encapsulation for GIST messages [RFC5971]
pt-tls 271 tcp IETF Network Endpoint Assessment (NEA) Posture Transport Protocol over TLS (PT-TLS) [IESG] [IETF_Chair] 2012-07-31 [RFC6876]
271 udp Reserved
272-279 Unassigned
http-mgmt 280 tcp http-mgmt [Adrian_Pell] [Adrian_Pell]
http-mgmt 280 udp http-mgmt [Adrian_Pell] [Adrian_Pell]
personal-link 281 tcp Personal Link [Dan_Cummings] [Dan_Cummings]
personal-link 281 udp Personal Link [Dan_Cummings] [Dan_Cummings]
cableport-ax 282 tcp Cable Port A/X [Craig_Langfahl] [Craig_Langfahl]
cableport-ax 282 udp Cable Port A/X [Craig_Langfahl] [Craig_Langfahl]
rescap 283 tcp rescap [Paul_Hoffman] [Paul_Hoffman]
rescap 283 udp rescap [Paul_Hoffman] [Paul_Hoffman]
corerjd 284 tcp corerjd [Chris_Thornhill] [Chris_Thornhill]
corerjd 284 udp corerjd [Chris_Thornhill] [Chris_Thornhill]
285 Unassigned
fxp 286 tcp FXP Communication [James_Darnall] [James_Darnall]
fxp 286 udp FXP Communication [James_Darnall] [James_Darnall]
k-block 287 tcp K-BLOCK [Simon_P_Jackson] [Simon_P_Jackson]
k-block 287 udp K-BLOCK [Simon_P_Jackson] [Simon_P_Jackson]
288-299 Unassigned
tacacss 300 tcp TLS Secure Login Host Protocol (TACACSS) [IESG] [IETF_Chair] 2025-07-15 [RFC-ietf-opsawg-tacacs-tls13-24]
vslmp 312 tcp VSLMP [Gerben_Wierda] [Gerben_Wierda]
vslmp 312 udp VSLMP [Gerben_Wierda] [Gerben_Wierda]
ptp-general 320 tcp PTP General [Kang_Lee] [Kang_Lee] 2010-07-27
ptp-general 320 udp PTP General [Kang_Lee] [Kang_Lee] 2010-07-27
pip 321 tcp PIP [Gordon_Mohr] [Gordon_Mohr]
pip 321 udp PIP [Gordon_Mohr] [Gordon_Mohr]
rtsps 322 tcp RTSPS [Anders_Klemets] [Anders_Klemets]
rtsps 322 udp RTSPS [Anders_Klemets] [Anders_Klemets]
rpki-rtr 323 tcp Resource PKI to Router Protocol [IESG] [IETF_Chair] [RFC6810]
323 udp Reserved
rpki-rtr-tls 324 tcp Resource PKI to Router Protocol over TLS [IESG] [IETF_Chair] [RFC6810]
324 udp Reserved
325-332 Unassigned
matip-type-a 350 tcp MATIP Type A [Alain_Robert] [Alain_Robert] [RFC2351]
matip-type-a 350 udp MATIP Type A [Alain_Robert] [Alain_Robert] [RFC2351]
matip-type-b 351 tcp MATIP Type B [Alain_Robert] [Alain_Robert] [RFC2351]
matip-type-b 351 udp MATIP Type B [Alain_Robert] [Alain_Robert] [RFC2351]
bhoetty 351 tcp bhoetty [John_Kelly] [John_Kelly] This entry records an unassigned but widespread use (added 5/21/97)
bhoetty 351 udp bhoetty [John_Kelly] [John_Kelly] This entry records an unassigned but widespread use (added 5/21/97)
dtag-ste-sb 352 tcp DTAG [Ruediger_Wald] [Ruediger_Wald] (assigned long ago)
dtag-ste-sb 352 udp DTAG [Ruediger_Wald] [Ruediger_Wald] (assigned long ago)
bhoedap4 352 tcp bhoedap4 [John_Kelly] [John_Kelly] This entry records an unassigned but widespread use (added 5/21/97)
bhoedap4 352 udp bhoedap4 [John_Kelly] [John_Kelly] This entry records an unassigned but widespread use (added 5/21/97)
359 tcp Reserved 2023-11-16 De-Assigned on 2023-11-16.
359 udp Reserved 2023-11-16 De-Assigned on 2023-11-16.
scoi2odialog 360 tcp scoi2odialog [Keith_Petley] [Keith_Petley]
scoi2odialog 360 udp scoi2odialog [Keith_Petley] [Keith_Petley]
srssend 362 tcp SRS Send [Curt_Mayer] [Curt_Mayer]
srssend 362 udp SRS Send [Curt_Mayer] [Curt_Mayer]
rpc2portmap 369 tcp rpc2portmap
rpc2portmap 369 udp rpc2portmap
codaauth2 370 tcp codaauth2 [Robert_Watson] [Robert_Watson]
codaauth2 370 udp codaauth2 [Robert_Watson] [Robert_Watson]
ulistproc 372 tcp ListProcessor [Anastasios_Kotsikona] [Anastasios_Kotsikona]
ulistproc 372 udp ListProcessor [Anastasios_Kotsikona] [Anastasios_Kotsikona]
legent-2 374 tcp Legent Corporation [Keith_Boyce] [Keith_Boyce]
legent-2 374 udp Legent Corporation [Keith_Boyce] [Keith_Boyce]
hp-managed-node 382 tcp hp performance data managed node
hp-managed-node 382 udp hp performance data managed node
unidata-ldm 388 tcp Unidata LDM [University_Corporation_for_Atmospheric_Research2] [Steven_Emmerson2] 2012-05-18
unidata-ldm 388 udp Unidata LDM [University_Corporation_for_Atmospheric_Research2] [Steven_Emmerson2] 2012-05-18
synotics-broker 392 tcp SynOptics Port Broker Port [Illan_Raab] [Illan_Raab]
synotics-broker 392 udp SynOptics Port Broker Port [Illan_Raab] [Illan_Raab]
iso-tsap-c2 399 tcp ISO Transport Class 2 Non-Control over TCP [Yanick_Pouffary] [Yanick_Pouffary]
iso-tsap-c2 399 udp ISO Transport Class 2 Non-Control over UDP [Yanick_Pouffary] [Yanick_Pouffary]
genie 402 tcp Genie Protocol [Mark_Hankin] [Mark_Hankin]
genie 402 udp Genie Protocol [Mark_Hankin] [Mark_Hankin]
synoptics-trap 412 tcp Trap Convention Port [Illan_Raab] [Illan_Raab]
synoptics-trap 412 udp Trap Convention Port [Illan_Raab] [Illan_Raab]
smpte 420 tcp SMPTE [Si_Becker] [Si_Becker]
smpte 420 udp SMPTE [Si_Becker] [Si_Becker]
ariel2 421 tcp Ariel 2
ariel2 421 udp Ariel 2
ariel3 422 tcp Ariel 3 [Joel_Karafin] [Joel_Karafin]
ariel3 422 udp Ariel 3 [Joel_Karafin] [Joel_Karafin]
opc-job-start 423 tcp IBM Operations Planning and Control Start
opc-job-start 423 udp IBM Operations Planning and Control Start
opc-job-track 424 tcp IBM Operations Planning and Control Track [Conny_Larsson] [Conny_Larsson]
opc-job-track 424 udp IBM Operations Planning and Control Track [Conny_Larsson] [Conny_Larsson]
icad-el 425 tcp ICAD [Larry_Stone] [Larry_Stone]
icad-el 425 udp ICAD [Larry_Stone] [Larry_Stone]
smartsdp 426 tcp smartsdp [Marie_Pierre_Belange] [Marie_Pierre_Belange]
smartsdp 426 udp smartsdp [Marie_Pierre_Belange] [Marie_Pierre_Belange]
svrloc 427 tcp Server Location [Veizades] [Veizades]
svrloc 427 udp Server Location [Veizades] [Veizades]
ocs-cmu 428 tcp OCS_CMU

IANA assigned this well-formed service name as a replacement for "ocs_cmu".
ocs_cmu 428 tcp OCS_CMU This entry is an alias to "ocs-cmu". This entry is now historic, not usable for use with many common service discovery mechanisms.
ocs-cmu 428 udp OCS_CMU

IANA assigned this well-formed service name as a replacement for "ocs_cmu".
ocs_cmu 428 udp OCS_CMU This entry is an alias to "ocs-cmu". This entry is now historic, not usable for use with many common service discovery mechanisms.
ocs-amu 429 tcp OCS_AMU

IANA assigned this well-formed service name as a replacement for "ocs_amu".
[Florence_Wyman] [Florence_Wyman]
ocs_amu 429 tcp OCS_AMU [Florence_Wyman] [Florence_Wyman] This entry is an alias to "ocs-amu". This entry is now historic, not usable for use with many common service discovery mechanisms.
ocs-amu 429 udp OCS_AMU

IANA assigned this well-formed service name as a replacement for "ocs_amu".
[Florence_Wyman] [Florence_Wyman]
ocs_amu 429 udp OCS_AMU [Florence_Wyman] [Florence_Wyman] This entry is an alias to "ocs-amu". This entry is now historic, not usable for use with many common service discovery mechanisms.
iasd 432 tcp IASD [Nir_Baroz] [Nir_Baroz]
iasd 432 udp IASD [Nir_Baroz] [Nir_Baroz]

Contact Information

ID Name Organization Contact URI Last Updated
[Adrian_Pell] Adrian Pell mailto:PELL_ADRIAN/HP-UnitedKingdom_om6@hplb.hpl.hp.com
[Alain_Robert] Alain Robert mailto:arobert&par.sita.int
[Anastasios_Kotsikona] Anastasios Kotsikonas mailto:tasos&cs.bu.edu
[Anders_Klemets] Anders Klemets mailto:anderskl&microsoft.com
[Chris_Thornhill] Chris Thornhill mailto:port_contact&cjt.ca
[Conny_Larsson] Conny Larsson mailto:cocke&vnet.ibm.com
[Craig_Langfahl] Craig Langfahl mailto:Craig_J_Langfahl&ccm.ch.intel.com
[Curt_Mayer] Curt Mayer mailto:curt&emergent.com
[Dan_Cummings] Dan Cummings mailto:doc&cnr.com
[Florence_Wyman] Florence Wyman mailto:wyman&peabody.plk.af.mil
[Franz_Josef_Leuders] Franz-Josef Leuders mailto:development&tobit.com
[Gerben_Wierda] Gerben Wierda mailto:Gerben_Wierda&rna.nl
[Gordon_Mohr] Gordon Mohr mailto:gojomo&usa.net
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Illan_Raab] Illan Raab mailto:iraab&synoptics.com
[James_Darnall] James Darnall mailto:james_r_darnall&sbcglobal.net
[Joel_Karafin] Joel Karafin mailto:jkarafin&infotrieve.com
[John_Kelly] John Kelly mailto:johnk&bellhow.com
[Kang_Lee] Kang Lee I&M Society TC-9 mailto:kang.lee&nist.gov 2010-07-27
[Keith_Boyce] Keith Boyce
[Keith_Petley] Keith Petley mailto:keithp&sco.com
[Larry_Stone] Larry Stone mailto:lcs&icad.com
[Marie_Pierre_Belange] Marie-Pierre Belanger mailto:belanger_marie&emc.com
[Mark_Hankin] Mark Hankin
[Nir_Baroz] Nir Baroz mailto:nbaroz&encore.com
[Paul_Hoffman] Paul Hoffman mailto:phoffman&proper.com 2024-07-23
[Robert_Watson] Robert Watson mailto:robert&cyrus.watson.org
[Ruediger_Wald] Ruediger Wald mailto:wald&ez-darmstadt.telekom.de
[Si_Becker] Si Becker mailto:71362.22&compuserve.com
[Simon_P_Jackson] Simon P Jackson mailto:jacko&kring.co.uk
[Steven_Emmerson2] Steven Emmerson The University Corporation for Atmospheric Research mailto:support-ldm&unidata.ucar.edu 2012-05-18
[University_Corporation_for_Atmospheric_Research2] The University Corporation for Atmospheric Research mailto:support-ldm&unidata.ucar.edu 2012-05-18
[Veizades] mailto:veizades&ftp.com
[Yanick_Pouffary] Yanick Pouffary mailto:pouffary&taec.enet.dec.com