Service Name and Transport Protocol Port Number Registry
Last Updated
- 2026-10-22
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | tcp | Reserved | 2024-12-20 | RFC 6335 | |||||||
| 0 | udp | Reserved | 2024-12-20 | RFC 6335 | |||||||
| 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 | sctp | Discard | Randall Stewart | Randall Stewart | 2022-02-07 | RFC 9260 | ||||
| discard | 9 | dccp | Discard | Eddie Kohler | Eddie Kohler | RFC 4340 | 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 | RFC 9260 | ||||
| ftp | 21 | sctp | FTP | Randall Stewart | Randall Stewart | 2022-02-07 | RFC 9260 | Defined TXT keys: u=<username> p=<password> path=<path> | |||
| ssh | 22 | sctp | SSH | Randall Stewart | Randall Stewart | 2022-02-07 | RFC 9260 | 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 | 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. | |||
| 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 | RFC 9260 | Defined TXT keys: u=<username> p=<password> path=<path to document> | |||
| 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 | ||||
| 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 | RFC 5905 | |||||
| ntp | 123 | udp | Network Time Protocol | Dave Mills | Dave Mills | RFC 5905 | |||||
| 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 | RFC 3501; RFC 9051 | ||||
| 143 | udp | Reserved | 2021-02-22 | RFC 9051 | |||||||
| 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 | RFC 9260 | ||||
| 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 |
Contact Information
| Name | Organization | Contact URI | Last Updated |
|---|---|---|---|
| B. Clifford Neuman | bcn&isi.edu | 2022-02-18 | |
| Bernie Volz | volz&cisco.com | ||
| Brian Reid | reid&decwrl.dec.com | ||
| C. Philip Wood | cpw&lanl.gov | ||
| Charles Watt | watt&sware.com | ||
| Dave Buehmann | ingr!daveb&uunet.uu.net | ||
| Dave Mills | mills&udel.edu | 2022-06-03 | |
| Eddie Kohler | IETF dccp WG | kohler&cs.ucla.edu | |
| Gerald McBrearty | |||
| 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 | ||
| Mark McCahill | mpm&boombox.micro.umn.edu | ||
| Marshall Rose | mrose17&gmail.com | 2024-07-29 | |
| Martin Hamilton | martin&mrrl.lut.as.uk | ||
| Martin Picard | |||
| Marty Schoffstahl | schoff&nisc.nyser.net | ||
| Marvin Solomon | solomon&cs.wisc.edu | ||
| Patrick McNamee | |||
| Randall Stewart | IETF TSVWG | rrs&lakerest.net | |
| Steve Dorner | s-dorner&uiuc.edu | ||
| Tim Berners-Lee | timbl&w3.org |