Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2024-12-20
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
0 tcp Reserved 2024-12-20 [RFC6335]
0 udp Reserved 2024-12-20 [RFC6335]
discard 9 sctp Discard [Randall_Stewart] [Randall_Stewart] 2022-02-07 [RFC9260]
discard 9 dccp Discard [Eddie_Kohler] [Eddie_Kohler] [RFC4340] 1145656131
10 tcp Unassigned
10 udp Unassigned
ftp-data 20 tcp File Transfer [Default Data] [Jon_Postel] [Jon_Postel]
ftp-data 20 udp File Transfer [Default Data] [Jon_Postel] [Jon_Postel]
ftp-data 20 sctp FTP [Randall_Stewart] [Randall_Stewart] 2022-02-07 [RFC9260]
ftp 21 sctp FTP [Randall_Stewart] [Randall_Stewart] 2022-02-07 [RFC9260] Defined TXT keys: u=<username> p=<password> path=<path>
ssh 22 sctp SSH [Randall_Stewart] [Randall_Stewart] 2022-02-07 [RFC9260] Defined TXT keys: u=<username> p=<password>
30 tcp Unassigned
30 udp Unassigned
40 tcp Unassigned
40 udp Unassigned
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.
re-mail-ck 50 tcp Remote Mail Checking Protocol [Steve_Dorner] [Steve_Dorner]
re-mail-ck 50 udp Remote Mail Checking Protocol [Steve_Dorner] [Steve_Dorner]
51 Reserved 2013-05-24 This entry is being removed on 2013-05-24.
60 tcp Unassigned
60 udp Unassigned
61 tcp Reserved 2017-05-18 This entry has been removed on 2017-05-18.
61 udp Reserved 2017-05-18 This entry has been removed on 2017-05-18.
gopher 70 tcp Gopher [Mark_McCahill] [Mark_McCahill]
gopher 70 udp Gopher [Mark_McCahill] [Mark_McCahill]
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.
www-http 80 tcp World Wide Web HTTP [Tim_Berners_Lee] [Tim_Berners_Lee] This is a duplicate of the "http" service and should not be used for discovery purposes. u=<username> p=<password> path=<path to document> (see txtrecords.html#http) Known Subtypes: _printer NOTE: The meaning of this service type, though called just "http", actually denotes something more precise than just "any data transported using HTTP". The DNS-SD service type "http" should only be used to advertise content that: * is served over HTTP, * can be displayed by "typical" web browser client software, and * is intented primarily to be viewed by a human user. Of course, the definition of "typical web browser" is subjective, and may change over time, but for practical purposes the DNS-SD service type "http" can be understood as meaning "human-readable HTML content served over HTTP". In some cases other widely-supported content types may also be appropriate, such as plain text over HTTP, or JPEG image over HTTP. Content types not intented primarily for viewing by a human user, or not widely-supported in web browsing clients, should not be advertised as DNS-SD service type "http", even if they do happen to be transported over HTTP. Such types should be advertised as their own logical service type with their own DNS-SD service type, for example, XUL (XML User Interface Language) transported over HTTP is advertised explicitly as DNS-SD service type "xul-http".
www-http 80 udp World Wide Web HTTP [Tim_Berners_Lee] [Tim_Berners_Lee] This is a duplicate of the "http" service and should not be used for discovery purposes. u=<username> p=<password> path=<path to document> (see txtrecords.html#http) Known Subtypes: _printer NOTE: The meaning of this service type, though called just "http", actually denotes something more precise than just "any data transported using HTTP". The DNS-SD service type "http" should only be used to advertise content that: * is served over HTTP, * can be displayed by "typical" web browser client software, and * is intented primarily to be viewed by a human user. Of course, the definition of "typical web browser" is subjective, and may change over time, but for practical purposes the DNS-SD service type "http" can be understood as meaning "human-readable HTML content served over HTTP". In some cases other widely-supported content types may also be appropriate, such as plain text over HTTP, or JPEG image over HTTP. Content types not intented primarily for viewing by a human user, or not widely-supported in web browsing clients, should not be advertised as DNS-SD service type "http", even if they do happen to be transported over HTTP. Such types should be advertised as their own logical service type with their own DNS-SD service type, for example, XUL (XML User Interface Language) transported over HTTP is advertised explicitly as DNS-SD service type "xul-http".
http 80 sctp HTTP [Randall_Stewart] [Randall_Stewart] 2022-02-07 [RFC9260] Defined TXT keys: u=<username> p=<password> path=<path to document>
kerberos 88 tcp Kerberos [B_Clifford_Neuman] [B_Clifford_Neuman] 2022-02-18 [RFC4120]
kerberos 88 udp Kerberos [B_Clifford_Neuman] [B_Clifford_Neuman] 2022-02-18 [RFC4120]
dnsix 90 tcp DNSIX Securit Attribute Token Map [Charles_Watt] [Charles_Watt] PORT 90 also being used unofficially by Pointcast
dnsix 90 udp DNSIX Securit Attribute Token Map [Charles_Watt] [Charles_Watt] PORT 90 also being used unofficially by Pointcast
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]
114 unassigned Deprecated June 2004
cfdptkt 120 tcp CFDPTKT [John_Ioannidis] [John_Ioannidis]
cfdptkt 120 udp CFDPTKT [John_Ioannidis] [John_Ioannidis]
ntp 123 tcp Network Time Protocol [Dave_Mills] [Dave_Mills] [RFC5905]
ntp 123 udp Network Time Protocol [Dave_Mills] [Dave_Mills] [RFC5905]
cisco-fna 130 tcp cisco FNATIVE
cisco-fna 130 udp cisco FNATIVE
emfis-data 140 tcp EMFIS Data Service
emfis-data 140 udp EMFIS Data Service
imap 143 tcp Internet Message Access Protocol [IESG] [IETF_Chair] 2021-02-22 [RFC3501][RFC9051]
143 udp Reserved 2021-02-22 [RFC9051]
iso-tp0 146 tcp ISO-IP0
iso-tp0 146 udp ISO-IP0
sql-net 150 tcp SQL-NET [Martin_Picard] [Martin_Picard]
sql-net 150 udp SQL-NET [Martin_Picard] [Martin_Picard]
sgmp-traps 160 tcp SGMP-TRAPS [Marty_Schoffstahl] [Marty_Schoffstahl]
sgmp-traps 160 udp SGMP-TRAPS [Marty_Schoffstahl] [Marty_Schoffstahl]
print-srv 170 tcp Network PostScript [Brian_Reid] [Brian_Reid]
print-srv 170 udp Network PostScript [Brian_Reid] [Brian_Reid]
bgp 179 sctp BGP [Randall_Stewart] [Randall_Stewart] 2022-02-07 [RFC9260]
ris 180 tcp Intergraph [Dave_Buehmann] [Dave_Buehmann]
ris 180 udp Intergraph [Dave_Buehmann] [Dave_Buehmann]
gacp 190 tcp Gateway Access Control Protocol [C_Philip_Wood] [C_Philip_Wood]
gacp 190 udp Gateway Access Control Protocol [C_Philip_Wood] [C_Philip_Wood]
src 200 tcp IBM System Resource Controller [Gerald_McBrearty] [Gerald_McBrearty]
src 200 udp IBM System Resource Controller [Gerald_McBrearty] [Gerald_McBrearty]
at-rtmp 201 tcp AppleTalk Routing Maintenance
at-rtmp 201 udp AppleTalk Routing Maintenance
at-nbp 202 tcp AppleTalk Name Binding
at-nbp 202 udp AppleTalk Name Binding
at-3 203 tcp AppleTalk Unused
at-3 203 udp AppleTalk Unused
at-echo 204 tcp AppleTalk Echo
at-echo 204 udp AppleTalk Echo
at-5 205 tcp AppleTalk Unused
at-5 205 udp AppleTalk Unused
at-zis 206 tcp AppleTalk Zone Information
at-zis 206 udp AppleTalk Zone Information
at-7 207 tcp AppleTalk Unused
at-7 207 udp AppleTalk Unused

Contact Information

ID Name Organization Contact URI Last Updated
[B_Clifford_Neuman] B. Clifford Neuman mailto:bcn&isi.edu 2022-02-18
[Brian_Reid] Brian Reid mailto:reid&decwrl.dec.com
[C_Philip_Wood] C. Philip Wood mailto:cpw&lanl.gov
[Charles_Watt] Charles Watt mailto:watt&sware.com
[Dave_Buehmann] Dave Buehmann mailto:ingr!daveb&uunet.uu.net
[Dave_Mills] Dave Mills mailto:mills&udel.edu 2022-06-03
[Eddie_Kohler] Eddie Kohler IETF dccp WG mailto:kohler&cs.ucla.edu
[Gerald_McBrearty] Gerald McBrearty
[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_Ioannidis] John Ioannidis mailto:ji&close.cs.columbia.ed
[Jon_Postel] Jon Postel mailto:postel&isi.edu
[Joyce_K_Reynolds] Joyce K. Reynolds mailto:jkrey&isi.edu
[Kevin_Murphy] Kevin Murphy mailto:murphy&sevens.lkg.dec.com
[Mark_McCahill] Mark McCahill mailto:mpm&boombox.micro.umn.edu
[Marshall_Rose] Marshall Rose mailto:mrose17&gmail.com 2024-07-29
[Martin_Hamilton] Martin Hamilton mailto:martin&mrrl.lut.as.uk
[Martin_Picard] Martin Picard
[Marty_Schoffstahl] Marty Schoffstahl mailto:schoff&nisc.nyser.net
[Marvin_Solomon] Marvin Solomon mailto:solomon&cs.wisc.edu
[Patrick_McNamee] Patrick McNamee
[Randall_Stewart] Randall Stewart IETF TSVWG mailto:rrs&lakerest.net
[Steve_Dorner] Steve Dorner mailto:s-dorner&uiuc.edu
[Tim_Berners_Lee] Tim Berners-Lee mailto:timbl&w3.org