Service Name and Transport Protocol Port Number Registry
Last Updated
- 2026-10-13
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
- RFC 6335: Internet Assigned Numbers Authority (IANA) Procedures for the Management of the Service Name and Transport Protocol Port Number Registry
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 basis, as described in RFC 6335.
Port numbers are divided into three ranges, with their uses and assignment procedures specified in Section 8.1.2 of RFC 6335:
- System Ports (0-1023) are assigned using the IETF Review or IESG Approval procedures.
- User Ports (1024-49151) are assigned using the IETF Review, IESG Approval, or Expert Review procedures.
- Dynamic and/or Private Ports (49152-65535) are not assigned.
The registration procedures for service names and port numbers are specified in RFC 6335, while the registration policies referenced above are defined in RFC 8126.
Assigned ports both System and User ports SHOULD NOT be used without or prior to IANA registration.
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.
Registration Forms
- To request a new assignment, please use the Application for Service Names and User Port Numbers form.
- To modify an existing assignment, please use the Modify a Port Number Assignment form.
Available Formats
| Service Name | Port Number | Transport Protocol | Description | Assignee | Contact | Registration Date | Modification Date | Reference | Service Code | Unauthorized Use Reported | Assignment Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| tcpmux | 1 | tcp | TCP Port Service Multiplexer | Mark Lottor | Mark Lottor | ||||||
| tcpmux | 1 | udp | TCP Port Service Multiplexer | Mark Lottor | Mark Lottor | ||||||
| 2 | tcp | Reserved | 2025-02-13 | De-assigned on 2025-02-13, previously compressnet by Bernie Volz | |||||||
| 2 | udp | Reserved | 2025-02-13 | De-assigned on 2025-02-13, previously compressnet by Bernie Volz | |||||||
| 3 | tcp | Reserved | 2025-02-13 | De-assigned on 2025-02-13, previously compressnet by Bernie Volz | |||||||
| 3 | udp | Reserved | 2025-02-13 | De-assigned on 2025-02-13, previously compressnet by Bernie Volz | |||||||
| discard | 9 | dccp | Discard | Eddie Kohler | Eddie Kohler | RFC 4340 | 1145656131 | ||||
| 10 | tcp | Unassigned | |||||||||
| 10 | udp | Unassigned | |||||||||
| systat | 11 | tcp | Active Users | Jon Postel | Jon Postel | ||||||
| systat | 11 | udp | Active Users | Jon Postel | Jon Postel | ||||||
| 12 | tcp | Unassigned | |||||||||
| 12 | udp | Unassigned | |||||||||
| daytime | 13 | tcp | Daytime | Jon Postel | Jon Postel | RFC 867 | |||||
| daytime | 13 | udp | Daytime | Jon Postel | Jon Postel | RFC 867 | |||||
| 14 | tcp | Unassigned | |||||||||
| 14 | udp | Unassigned | |||||||||
| 15 | tcp | Unassigned [was netstat] | |||||||||
| 15 | udp | Unassigned | |||||||||
| 16 | tcp | Unassigned | |||||||||
| 16 | udp | Unassigned | |||||||||
| qotd | 17 | tcp | Quote of the Day | Jon Postel | Jon Postel | ||||||
| qotd | 17 | udp | Quote of the Day | Jon Postel | Jon Postel | ||||||
| msp | 18 | tcp | Message Send Protocol (historic) | Rina Nethaniel | Rina Nethaniel | ||||||
| msp | 18 | udp | Message Send Protocol (historic) | Rina Nethaniel | Rina Nethaniel | ||||||
| chargen | 19 | tcp | Character Generator | ||||||||
| chargen | 19 | udp | Character Generator | ||||||||
| ftp | 21 | tcp | File Transfer Protocol [Control] | Jon Postel | Jon Postel | RFC 959 | Defined TXT keys: u=<username> p=<password> path=<path> | ||||
| ftp | 21 | udp | File Transfer Protocol [Control] | Jon Postel | Jon Postel | RFC 959 | Defined TXT keys: u=<username> p=<password> path=<path> | ||||
| ftp | 21 | sctp | FTP | Randall Stewart | Randall Stewart | 2022-02-07 | RFC 9260 | Defined TXT keys: u=<username> p=<password> path=<path> | |||
| ssh | 22 | tcp | The Secure Shell (SSH) Protocol | RFC 4251 | Defined TXT keys: u=<username> p=<password> | ||||||
| ssh | 22 | udp | The Secure Shell (SSH) Protocol | RFC 4251 | Defined TXT keys: u=<username> p=<password> | ||||||
| smtp | 25 | tcp | Simple Mail Transfer | IESG | IETF Chair | 2017-06-05 | RFC-ietf-emailcore-rfc5321bis-43 | ||||
| smtp | 25 | udp | Simple Mail Transfer | IESG | IETF Chair | 2017-06-05 | RFC-ietf-emailcore-rfc5321bis-43 | ||||
| msg-auth | 31 | tcp | MSG Authentication | Robert Thomas | Robert Thomas | ||||||
| msg-auth | 31 | udp | MSG Authentication | Robert Thomas | Robert Thomas | ||||||
| graphics | 41 | tcp | Graphics | ||||||||
| graphics | 41 | udp | Graphics | ||||||||
| 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. | |||||||
| 51 | Reserved | 2013-05-24 | This entry is being removed on 2013-05-24. | ||||||||
| 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. | |||||||
| bootps | 67 | tcp | Bootstrap Protocol Server | Bill Croft | Bill Croft | RFC 951 | Defined TXT keys: None | ||||
| netrjs-1 | 71 | tcp | Remote Job Service | ||||||||
| netrjs-1 | 71 | udp | Remote Job Service | ||||||||
| finger | 79 | tcp | Finger | David Zimmerman | David Zimmerman | Unauthorized use by some mail users (see [RFC4146] for details) | |||||
| finger | 79 | udp | Finger | David Zimmerman | David Zimmerman | Unauthorized use by some mail users (see [RFC4146] for details) | |||||
| http | 80 | tcp | World Wide Web HTTP | IESG | IETF Chair | 2021-10-01 | RFC 9110 | Defined TXT keys: u=<username> p=<password> path=<path to document> | |||
| http | 80 | udp | World Wide Web HTTP | IESG | IETF Chair | 2021-10-01 | RFC 9110 | Defined TXT keys: u=<username> p=<password> path=<path to document> | |||
| www | 80 | tcp | World Wide Web HTTP | IESG | IETF Chair | 2021-10-01 | RFC 9110 | 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 | RFC 9110 | This is a duplicate of the "http" service and should not be used for discovery purposes. | |||
| 81 | Unassigned | 2007-09-06 | |||||||||
| kerberos | 88 | tcp | Kerberos | B. Clifford Neuman | B. Clifford Neuman | 2022-02-18 | RFC 4120 | ||||
| kerberos | 88 | udp | Kerberos | B. Clifford Neuman | B. Clifford Neuman | 2022-02-18 | RFC 4120 | ||||
| mit-dov | 91 | tcp | MIT Dover Spooler | Eliot Moss | Eliot Moss | ||||||
| mit-dov | 91 | udp | MIT Dover Spooler | Eliot Moss | Eliot Moss | ||||||
| 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 | ||||||
| sunrpc | 111 | tcp | SUN Remote Procedure Call | Chuck McManis | Chuck McManis | ||||||
| sunrpc | 111 | udp | SUN Remote Procedure Call | Chuck McManis | Chuck McManis | ||||||
| mcidas | 112 | tcp | McIDAS Data Transmission Protocol | Glenn Davis | Glenn Davis | ||||||
| mcidas | 112 | udp | McIDAS Data Transmission Protocol | Glenn Davis | Glenn Davis | ||||||
| ident | 113 | tcp | |||||||||
| auth | 113 | tcp | Authentication Service | Mike St. Johns | Mike St. Johns | ||||||
| auth | 113 | udp | Authentication Service | Mike St. Johns | Mike St. Johns | ||||||
| 114 | unassigned | Deprecated June 2004 | |||||||||
| sftp | 115 | tcp | Simple File Transfer Protocol | Mark Lottor | Mark Lottor | ||||||
| sftp | 115 | udp | Simple File Transfer Protocol | Mark Lottor | Mark Lottor | ||||||
| ansanotify | 116 | tcp | ANSA REX Notify | Nicola J. Howarth | Nicola J. Howarth | ||||||
| ansanotify | 116 | udp | ANSA REX Notify | Nicola J. Howarth | Nicola J. Howarth | ||||||
| uucp-path | 117 | tcp | UUCP Path Service | ||||||||
| uucp-path | 117 | udp | UUCP Path Service | ||||||||
| sqlserv | 118 | tcp | SQL Services | Larry Barnes | Larry Barnes | ||||||
| sqlserv | 118 | udp | SQL Services | Larry Barnes | Larry Barnes | ||||||
| nntp | 119 | tcp | Network News Transfer Protocol | IESG | IETF Chair | 2018-07-06 | RFC 3977 | ||||
| nntp | 119 | udp | Network News Transfer Protocol | IESG | IETF Chair | 2018-07-06 | RFC 3977 | ||||
| cfdptkt | 120 | tcp | CFDPTKT | John Ioannidis | John Ioannidis | ||||||
| cfdptkt | 120 | udp | CFDPTKT | John Ioannidis | John Ioannidis |
Contact Information
| Name | Organization | Contact URI | Last Updated |
|---|---|---|---|
| B. Clifford Neuman | bcn&isi.edu | 2022-02-18 | |
| Bernie Volz | volz&cisco.com | ||
| Bill Croft | Croft&sumex-aim.stanford.edu | ||
| Chuck McManis | cmcmanis&freegate.net | ||
| David Zimmerman | dpz&rutgers.edu | ||
| Eddie Kohler | IETF dccp WG | kohler&cs.ucla.edu | |
| Eliot Moss | EBM&xx.lcs.mit.edu | ||
| Glenn Davis | support&unidata.ucar.edu | ||
| IESG | iesg&ietf.org | ||
| IETF Chair | IETF | chair&ietf.org | |
| Jeremy Siegel | jzs&nsd.3com.com | ||
| John Ioannidis | ji&close.cs.columbia.ed | ||
| Jon Postel | postel&isi.edu | ||
| Joyce K. Reynolds | jkrey&isi.edu | ||
| Kevin Murphy | murphy&sevens.lkg.dec.com | ||
| Larry Barnes | barnes&broke.enet.dec.com | ||
| Mark Lottor | MKL&nisc.sri.com | ||
| Marshall Rose | mrose17&gmail.com | 2024-07-29 | |
| Martin Hamilton | martin&mrrl.lut.as.uk | ||
| Marvin Solomon | solomon&cs.wisc.edu | ||
| Mike St. Johns | stjohns&arpa.mil | ||
| Nicola J. Howarth | njh&ansa.co.uk | ||
| Patrick McNamee | |||
| Randall Stewart | IETF TSVWG | rrs&lakerest.net | |
| Rina Nethaniel | |||
| Robert Thomas | BThomas&f.bbn.com |