Service Name and Transport Protocol Port Number Registry

Last Updated
2026-09-11
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
0 tcp Reserved 2024-12-20 [RFC6335]
0 udp Reserved 2024-12-20 [RFC6335]
whoispp 63 tcp whois++

IANA assigned this well-formed service name as a replacement for "whois++".
[Rickard_Schoultz] [Rickard_Schoultz]
whois++ 63 tcp whois++ [Rickard_Schoultz] [Rickard_Schoultz] This entry is an alias to "whoispp". This entry is now historic, not usable for use with many common service discovery mechanisms.
whoispp 63 udp whois++

IANA assigned this well-formed service name as a replacement for "whois++".
[Rickard_Schoultz] [Rickard_Schoultz]
whois++ 63 udp whois++ [Rickard_Schoultz] [Rickard_Schoultz] This entry is an alias to "whoispp". This entry is now historic, not usable for use with many common service discovery mechanisms.
cmip-man 163 tcp CMIP/TCP Manager
cmip-man 163 udp CMIP/TCP Manager
hdap 263 tcp HDAP [Troy_Gau] [Troy_Gau]
hdap 263 udp HDAP [Troy_Gau] [Troy_Gau]
rsvp-tunnel 363 tcp RSVP Tunnel

IANA assigned this well-formed service name as a replacement for "rsvp_tunnel".
[Andreas_Terzis] [Andreas_Terzis]
rsvp_tunnel 363 tcp RSVP Tunnel [Andreas_Terzis] [Andreas_Terzis] This entry is an alias to "rsvp-tunnel". This entry is now historic, not usable for use with many common service discovery mechanisms.
rsvp-tunnel 363 udp RSVP Tunnel

IANA assigned this well-formed service name as a replacement for "rsvp_tunnel".
[Andreas_Terzis] [Andreas_Terzis]
rsvp_tunnel 363 udp RSVP Tunnel [Andreas_Terzis] [Andreas_Terzis] This entry is an alias to "rsvp-tunnel". This entry is now historic, not usable for use with many common service discovery mechanisms.
alpes 463 tcp alpes [Alain_Durand] [Alain_Durand]
alpes 463 udp alpes [Alain_Durand] [Alain_Durand]
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]
rda 630 tcp RDA [John_Hadjioannou] [John_Hadjioannou]
rda 630 udp RDA [John_Hadjioannou] [John_Hadjioannou]
ipp 631 tcp IPP (Internet Printing Protocol) [IESG] [IETF_Chair] 2018-07-06 [RFC8011] Defined TXT keys: See BonjourPrinting.pdf.
ipp 631 udp IPP (Internet Printing Protocol) [IESG] [IETF_Chair] 2018-07-06 [RFC8011] Defined TXT keys: See BonjourPrinting.pdf.
ipps 631 tcp Internet Printing Protocol over HTTPS [IESG] [IETF_Chair] 2018-07-06 [RFC8011]
bmpp 632 tcp bmpp [Troy_Rollo] [Troy_Rollo]
bmpp 632 udp bmpp [Troy_Rollo] [Troy_Rollo]
servstat 633 tcp Service Status update (Sterling Software) [Greg_Rose] [Greg_Rose]
servstat 633 udp Service Status update (Sterling Software) [Greg_Rose] [Greg_Rose]
ginad 634 tcp ginad [Mark_Crother] [Mark_Crother]
ginad 634 udp ginad [Mark_Crother] [Mark_Crother]
rlzdbase 635 tcp RLZ DBase [Michael_Ginn] [Michael_Ginn]
rlzdbase 635 udp RLZ DBase [Michael_Ginn] [Michael_Ginn]
ldaps 636 tcp ldap protocol over TLS/SSL (was sldap) [Pat_Richard] [Pat_Richard]
ldaps 636 udp ldap protocol over TLS/SSL (was sldap) [Pat_Richard] [Pat_Richard]
lanserver 637 tcp lanserver [Chris_Larsson] [Chris_Larsson]
lanserver 637 udp lanserver [Chris_Larsson] [Chris_Larsson]
mcns-sec 638 tcp mcns-sec [Kaz_Ozawa] [Kaz_Ozawa]
mcns-sec 638 udp mcns-sec [Kaz_Ozawa] [Kaz_Ozawa]
msdp 639 tcp MSDP [Dino_Farinacci] [Dino_Farinacci]
msdp 639 udp MSDP [Dino_Farinacci] [Dino_Farinacci]
purenoise 663 tcp PureNoise [Sam_Osa] [Sam_Osa]
purenoise 663 udp PureNoise [Sam_Osa] [Sam_Osa]
cycleserv 763 tcp
cycleserv 763 udp
863-872 Unassigned
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]
1023 tcp Reserved 2024-12-20 [RFC6335]
1023 udp Reserved 2024-12-20 [RFC6335]
1024 tcp Reserved 2024-12-20 [RFC6335]
1024 udp Reserved 2024-12-20 [RFC6335]
kyoceranetdev 1063 tcp KyoceraNetDev [Shigenaka_Kanemitsu] [Shigenaka_Kanemitsu]
kyoceranetdev 1063 udp KyoceraNetDev [Shigenaka_Kanemitsu] [Shigenaka_Kanemitsu]
sddp 1163 tcp SmartDialer Data Protocol [Lee_Griffiths] [Lee_Griffiths] 2004-11
sddp 1163 udp SmartDialer Data Protocol [Lee_Griffiths] [Lee_Griffiths] 2004-11
dka 1263 tcp dka [Chris_Griffin] [Chris_Griffin]
dka 1263 udp dka [Chris_Griffin] [Chris_Griffin]
ndm-requester 1363 tcp Network DataMover Requester
ndm-requester 1363 udp Network DataMover Requester
nucleus 1463 tcp Nucleus [Venky_Nagar] [Venky_Nagar]
nucleus 1463 udp Nucleus [Venky_Nagar] [Venky_Nagar]
cadabra-lm 1563 tcp Cadabra License Manager [Arthur_Castonguay] [Arthur_Castonguay]
cadabra-lm 1563 udp Cadabra License Manager [Arthur_Castonguay] [Arthur_Castonguay]
oraclenet8cman 1630 tcp Oracle Net8 Cman [Tong_Ming_Lee] [Tong_Ming_Lee]
oraclenet8cman 1630 udp Oracle Net8 Cman [Tong_Ming_Lee] [Tong_Ming_Lee]
visitview 1631 tcp Visit view [Tom_Whittaker] [Tom_Whittaker]
visitview 1631 udp Visit view [Tom_Whittaker] [Tom_Whittaker]
pammratc 1632 tcp PAMMRATC
pammratc 1632 udp PAMMRATC
pammrpc 1633 tcp PAMMRPC [John_Britton] [John_Britton]
pammrpc 1633 udp PAMMRPC [John_Britton] [John_Britton]
loaprobe 1634 tcp Log On America Probe [James_Tavares] [James_Tavares]
loaprobe 1634 udp Log On America Probe [James_Tavares] [James_Tavares]
edb-server1 1635 tcp EDB Server 1 [Carlos_Portela] [Carlos_Portela]
edb-server1 1635 udp EDB Server 1 [Carlos_Portela] [Carlos_Portela]
isdc 1636 tcp ISP shared public data control
isdc 1636 udp ISP shared public data control
islc 1637 tcp ISP shared local data control
islc 1637 udp ISP shared local data control
ismc 1638 tcp ISP shared management control [Nick_Austin] [Nick_Austin]
ismc 1638 udp ISP shared management control [Nick_Austin] [Nick_Austin]
cert-initiator 1639 tcp cert-initiator
cert-initiator 1639 udp cert-initiator
netview-aix-3 1663 tcp netview-aix-3
netview-aix-3 1663 udp netview-aix-3
pptp 1723 tcp pptp [Ken_Crocker] [Ken_Crocker] 2021-09-21 [RFC2637]
pptp 1723 udp pptp [Ken_Crocker] [Ken_Crocker] 2021-09-21 [RFC2637]
cft-2 1763 tcp cft-2 [Martine_Marchand] [Martine_Marchand]
cft-2 1763 udp cft-2 [Martine_Marchand] [Martine_Marchand]
msnp 1863 tcp MSNP [William_Lai] [William_Lai]
msnp 1863 udp MSNP [William_Lai] [William_Lai]
webmachine 1963 tcp WebMachine [Tim_Jowers] [Tim_Jowers]
webmachine 1963 udp WebMachine [Tim_Jowers] [Tim_Jowers]
icg-bridge 2063 tcp ICG Bridge Port
icg-bridge 2063 udp ICG Bridge Port

Contact Information

ID Name Organization Contact URI Last Updated
[Alain_Durand] Alain Durand mailto:Alain.Durand&imag.fr
[Andreas_Terzis] Andreas Terzis mailto:terzis&cs.ucla.edu
[Arthur_Castonguay] Arthur Castonguay mailto:arthurc&doe.carleton.ca
[Carlos_Portela] Carlos Portela mailto:cportela&simple-sw.com 2003-02
[Chris_Griffin] Chris Griffin mailto:cgriffin&dka.com
[Chris_Larsson] Chris Larsson mailto:clarsson&vnet.ibm.com
[Dino_Farinacci] Dino Farinacci mailto:dino&cisco.com 2008-08-21
[Greg_Rose] Greg Rose mailto:Greg_Rose&sydney.sterling.com
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[James_Tavares] James Tavares Log On America mailto:krontor&loa.com
[John_Britton] John Britton mailto:johnb&peakaudio.com
[John_Hadjioannou] John Hadjioannou mailto:john&minster.co.uk
[Kaz_Ozawa] Kaz Ozawa mailto:k.ozawa&cablelabs.com
[Ken_Crocker] Ken Crocker mailto:kcrocker&microsoft.com
[Lee_Griffiths] Lee Griffiths mailto:lg&dataconnection.com 2004-11
[Mark_Crother] Mark Crother mailto:mark&eis.calstate.edu
[Martine_Marchand] Martine Marchand tel:+16-1-46-59-24-84
[Michael_Ginn] Michael Ginn mailto:ginn&tyxar.com
[Nick_Austin] Nick Austin mailto:ogmion&ogmium.com
[Pat_Richard] Pat Richard mailto:patr&xcert.com
[Rickard_Schoultz] Rickard Schoultz mailto:schoultz&sunet.se
[Sam_Osa] Sam Osa mailto:pristine&mailcity.com
[Shigenaka_Kanemitsu] Shigenaka Kanemitsu mailto:Shigenaka_Kanemitsu&ypd.kyocera.co.jp
[Tim_Jowers] Tim Jowers mailto:Tim.Jowers&columbiasc.ncr.com
[Tom_Whittaker] Tom Whittaker mailto:tomw&ssec.wisc.edu
[Tong_Ming_Lee] Tong-Ming Lee mailto:tmlee&us.oracle.com
[Troy_Gau] Troy Gau mailto:troy&zyxel.com
[Troy_Rollo] Troy Rollo mailto:troy&kroll.corvu.com.au
[Venky_Nagar] Venky Nagar mailto:venky&fafner.stanford.edu
[William_Lai] William Lai mailto:wlai&microsoft.com