Service Name and Transport Protocol Port Number Registry

Last Updated
2026-03-27
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
10 tcp Unassigned
10 udp Unassigned
http 80 tcp World Wide Web HTTP [IESG] [IETF_Chair] 2021-10-01 [RFC9110] Defined TXT keys: u=<username> p=<password> path=<path to document>
http 80 udp World Wide Web HTTP [IESG] [IETF_Chair] 2021-10-01 [RFC9110] Defined TXT keys: u=<username> p=<password> path=<path to document>
www 80 tcp World Wide Web HTTP [IESG] [IETF_Chair] 2021-10-01 [RFC9110] This is a duplicate of the "http" service and should not be used for discovery purposes.
www 80 udp World Wide Web HTTP [IESG] [IETF_Chair] 2021-10-01 [RFC9110] This is a duplicate of the "http" service and should not be used for discovery purposes.
100 Unassigned 2012-03-21 Known Unauthorized Use on 100
hostname 101 tcp NIC Host Name Server [Jon_Postel] [Jon_Postel]
hostname 101 udp NIC Host Name Server [Jon_Postel] [Jon_Postel]
iso-tsap 102 tcp ISO-TSAP Class 0 [Marshall_Rose] [Marshall_Rose]
iso-tsap 102 udp ISO-TSAP Class 0 [Marshall_Rose] [Marshall_Rose]
gppitnp 103 tcp Genesis Point-to-Point Trans Net
gppitnp 103 udp Genesis Point-to-Point Trans Net
acr-nema 104 tcp ACR-NEMA Digital Imag. & Comm. 300 [Patrick_McNamee] [Patrick_McNamee]
acr-nema 104 udp ACR-NEMA Digital Imag. & Comm. 300 [Patrick_McNamee] [Patrick_McNamee]
cso 105 tcp CCSO name server protocol [Martin_Hamilton] [Martin_Hamilton]
cso 105 udp CCSO name server protocol [Martin_Hamilton] [Martin_Hamilton]
csnet-ns 105 tcp Mailbox Name Nameserver [Marvin_Solomon] [Marvin_Solomon]
csnet-ns 105 udp Mailbox Name Nameserver [Marvin_Solomon] [Marvin_Solomon]
3com-tsmux 106 tcp 3COM-TSMUX [Jeremy_Siegel] [Jeremy_Siegel] Known Unauthorized Use on 106
3com-tsmux 106 udp 3COM-TSMUX [Jeremy_Siegel] [Jeremy_Siegel] Known Unauthorized Use on 106
rtelnet 107 tcp Remote Telnet Service [Jon_Postel] [Jon_Postel]
rtelnet 107 udp Remote Telnet Service [Jon_Postel] [Jon_Postel]
snagas 108 tcp SNA Gateway Access Server [Kevin_Murphy] [Kevin_Murphy]
snagas 108 udp SNA Gateway Access Server [Kevin_Murphy] [Kevin_Murphy]
pop2 109 tcp Post Office Protocol - Version 2 [Joyce_K_Reynolds] [Joyce_K_Reynolds]
pop2 109 udp Post Office Protocol - Version 2 [Joyce_K_Reynolds] [Joyce_K_Reynolds]
pop3 110 tcp Post Office Protocol - Version 3 [Marshall_Rose] [Marshall_Rose]
pop3 110 udp Post Office Protocol - Version 3 [Marshall_Rose] [Marshall_Rose]
z39-50 210 tcp ANSI Z39.50

IANA assigned this well-formed service name as a replacement for "z39.50".
[Mark_H_Needleman] [Mark_H_Needleman]
z39.50 210 tcp ANSI Z39.50 [Mark_H_Needleman] [Mark_H_Needleman] This entry is an alias to "z39-50". This entry is now historic, not usable for use with many common service discovery mechanisms.
z39-50 210 udp ANSI Z39.50

IANA assigned this well-formed service name as a replacement for "z39.50".
[Mark_H_Needleman] [Mark_H_Needleman]
z39.50 210 udp ANSI Z39.50 [Mark_H_Needleman] [Mark_H_Needleman] This entry is an alias to "z39-50". This entry is now historic, not usable for use with many common service discovery mechanisms.
225-241 Reserved 2024-12-20 [RFC1060]
249-255 Reserved 2024-12-20 [RFC1060]
bhmds 310 tcp bhmds [John_Kelly] [John_Kelly]
bhmds 310 udp bhmds [John_Kelly] [John_Kelly]
rpki-rtr 323 tcp Resource PKI to Router Protocol [IESG] [IETF_Chair] [RFC6810]
rpki-rtr-tls 324 tcp Resource PKI to Router Protocol over TLS [IESG] [IETF_Chair] [RFC6810]
decladebug 410 tcp DECLadebug Remote Debug Protocol [Hewlett_Packard] [Hewlett_Packard]
decladebug 410 udp DECLadebug Remote Debug Protocol [Hewlett_Packard] [Hewlett_Packard]
https 443 tcp http protocol over TLS/SSL [IESG] [IETF_Chair] 2021-10-01 [RFC9110]
https 443 udp http protocol over TLS/SSL [IESG] [IETF_Chair] 2021-10-01 [RFC9110]
fcp 510 tcp FirstClass Protocol [Mike_Marshburn] [Mike_Marshburn]
fcp 510 udp FirstClass Protocol [Mike_Marshburn] [Mike_Marshburn]
npmp-local 610 tcp npmp-local
npmp-local 610 udp npmp-local
entrust-ash 710 tcp Entrust Administration Service Handler [Peter_Whittaker] [Peter_Whittaker]
entrust-ash 710 udp Entrust Administration Service Handler [Peter_Whittaker] [Peter_Whittaker]
fcp-udp 810 tcp FCP [Paul_Whittemore] [Paul_Whittemore]
fcp-udp 810 udp FCP Datagram [Paul_Whittemore] [Paul_Whittemore]
kink 910 tcp Kerberized Internet Negotiation of Keys (KINK) [RFC4430]
kink 910 udp Kerberized Internet Negotiation of Keys (KINK) [RFC4430]
cadlock2 1000 tcp
cadlock2 1000 udp
webpush 1001 tcp HTTP Web Push [IESG] [IETF_Chair] 2016-11-01 [RFC8030]
1001 udp Reserved
1002-1007 Unassigned
1008 udp Possibly used by Sun Solaris????
1009 Unassigned
surf 1010 tcp surf [Joseph_Geer] [Joseph_Geer]
surf 1010 udp surf [Joseph_Geer] [Joseph_Geer]
1011-1020 Reserved
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]
blackjack 1025 tcp network blackjack
blackjack 1025 udp network blackjack
cap 1026 tcp Calendar Access Protocol [Doug_Royer] [Doug_Royer] 2010-12-09
cap 1026 udp Calendar Access Protocol [Doug_Royer] [Doug_Royer] 2010-12-09
6a44 1027 udp IPv6 Behind NAT44 CPEs [IESG] [IETF_Chair] 2012-08-02 [RFC6751]
1027 tcp Reserved
1028 Deprecated 2004-02
solid-mux 1029 tcp Solid Mux Server [Anders_Borg] [Anders_Borg] 2004-11
solid-mux 1029 udp Solid Mux Server [Anders_Borg] [Anders_Borg] 2004-11
1030 Reserved 2013-05-24 This entry is being removed on 2013-05-24.
1031 Reserved 2013-05-24 This entry is being removed on 2013-05-24.
1032 Reserved 2013-05-24 This entry is being removed on 2013-05-24.
netinfo-local 1033 tcp local netinfo port [Marc_Majka] [Marc_Majka] 2002-08
netinfo-local 1033 udp local netinfo port [Marc_Majka] [Marc_Majka] 2002-08
activesync 1034 tcp ActiveSync Notifications [Sandra_Vargas] [Sandra_Vargas] 2003-03
activesync 1034 udp ActiveSync Notifications [Sandra_Vargas] [Sandra_Vargas] 2003-03
mxxrlogin 1035 tcp MX-XR RPC [Valassis] [John_Eckert] 2003-04 2015-05-05
mxxrlogin 1035 udp MX-XR RPC [Valassis] [John_Eckert] 2003-04 2015-05-05
nsstp 1036 tcp Nebula Secure Segment Transfer Protocol [Steve_Ravida] [Steve_Ravida]
nsstp 1036 udp Nebula Secure Segment Transfer Protocol [Steve_Ravida] [Steve_Ravida]
ams 1037 tcp AMS [Ronald_R_Ohmer] [Ronald_R_Ohmer] 2004-02
ams 1037 udp AMS [Ronald_R_Ohmer] [Ronald_R_Ohmer] 2004-02
mtqp 1038 tcp Message Tracking Query Protocol [RFC3887]
mtqp 1038 udp Message Tracking Query Protocol [RFC3887]
sbl 1039 tcp Streamlined Blackhole [Jonathan_A_Zdziaras] [Jonathan_A_Zdziaras] 2004-11

Contact Information

ID Name Organization Contact URI Last Updated
[Anders_Borg] Anders Borg mailto:anders.borg&solid.se 2004-11
[Doug_Royer] Doug Royer mailto:DouglasRoyer&gmail.com 2010-12-09
[Hewlett_Packard] Hewlett Packard
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Jeremy_Siegel] Jeremy Siegel mailto:jzs&nsd.3com.com
[John_Eckert] John Eckert Valassis mailto:eckertj&valassis.com 2015-05-05
[John_Kelly] John Kelly mailto:johnk&bellhow.com
[Jon_Postel] Jon Postel mailto:postel&isi.edu
[Jonathan_A_Zdziaras] Jonathan A. Zdziaraski mailto:jonathan&nuclearelephant.com 2004-11
[Joseph_Geer] Joseph Geer mailto:jgeer&peapod.com
[Joyce_K_Reynolds] Joyce K. Reynolds mailto:jkrey&isi.edu
[Kevin_Murphy] Kevin Murphy mailto:murphy&sevens.lkg.dec.com
[Marc_Majka] Marc Majka mailto:majka&apple.com 2002-08
[Mark_H_Needleman] Mark H. Needleman mailto:markn&sirsi.com
[Marshall_Rose] Marshall Rose mailto:mrose17&gmail.com 2024-07-29
[Martin_Hamilton] Martin Hamilton mailto:martin&mrrl.lut.as.uk
[Marvin_Solomon] Marvin Solomon mailto:solomon&cs.wisc.edu
[Mike_Marshburn] Mike Marshburn mailto:paul&softarc.com
[Patrick_McNamee] Patrick McNamee
[Paul_Whittemore] Paul Whittemore mailto:paul&softarc.com
[Peter_Whittaker] Peter Whittaker mailto:pww&entrust.com
[Ronald_R_Ohmer] Ronald R. Ohmer mailto:rohmer&aisconsulting.net 2004-02
[Sandra_Vargas] Sandra Vargas mailto:Sandrama&microsoft.com 2003-03
[Steve_Ravida] Steve Ravida mailto:steve.ravida&nebulaholdings.com
[Valassis] Valassis mailto:eckertj&valassis.com 2015-05-05