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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| mpm-snd | 46 | tcp | MPM [default send] | Jon Postel | Jon Postel | ||||||
| mpm-snd | 46 | udp | MPM [default send] | Jon Postel | Jon Postel | ||||||
| 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. | |||||||
| auditd | 48 | tcp | Digital Audit Daemon | Larry Scott | Larry Scott | ||||||
| auditd | 48 | udp | Digital Audit Daemon | Larry Scott | Larry Scott | ||||||
| tacacs | 49 | tcp | Login Host Protocol (TACACS) | Pieter Ditmars | Pieter Ditmars | ||||||
| tacacs | 49 | udp | Login Host Protocol (TACACS) | Pieter Ditmars | Pieter Ditmars | ||||||
| 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. | ||||||||
| xns-time | 52 | tcp | XNS Time Protocol | Susie Armstrong | Susie Armstrong | ||||||
| xns-time | 52 | udp | XNS Time Protocol | Susie Armstrong | Susie Armstrong | ||||||
| domain | 53 | tcp | Domain Name Server | Paul Mockapetris | Paul Mockapetris | ||||||
| domain | 53 | udp | Domain Name Server | Paul Mockapetris | Paul Mockapetris | ||||||
| xns-ch | 54 | tcp | XNS Clearinghouse | Susie Armstrong | Susie Armstrong | ||||||
| xns-ch | 54 | udp | XNS Clearinghouse | Susie Armstrong | Susie Armstrong | ||||||
| isi-gl | 55 | tcp | ISI Graphics Language | ||||||||
| isi-gl | 55 | udp | ISI Graphics Language | ||||||||
| xns-auth | 56 | tcp | XNS Authentication | Susie Armstrong | Susie Armstrong | ||||||
| xns-auth | 56 | udp | XNS Authentication | Susie Armstrong | Susie Armstrong | ||||||
| 57 | tcp | any private terminal access | Jon Postel | Jon Postel | |||||||
| 57 | udp | any private terminal access | Jon Postel | Jon Postel | |||||||
| xns-mail | 58 | tcp | XNS Mail | Susie Armstrong | Susie Armstrong | ||||||
| xns-mail | 58 | udp | XNS Mail | Susie Armstrong | Susie Armstrong | ||||||
| 59 | tcp | any private file service | Jon Postel | Jon Postel | |||||||
| 59 | udp | any private file service | Jon Postel | Jon Postel | |||||||
| 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. | |||||||
| acas | 62 | tcp | ACA Services | E. Wald | E. Wald | ||||||
| acas | 62 | udp | ACA Services | E. Wald | E. Wald | ||||||
| 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. | |||||
| covia | 64 | tcp | Communications Integrator (CI) | Dan Smith | Dan Smith | ||||||
| covia | 64 | udp | Communications Integrator (CI) | Dan Smith | Dan Smith | ||||||
| tacacs-ds | 65 | tcp | TACACS-Database Service | Kathy Huber | Kathy Huber | ||||||
| tacacs-ds | 65 | udp | TACACS-Database Service | Kathy Huber | Kathy Huber | ||||||
| sql-net | 66 | tcp | Oracle SQL*NET IANA assigned this well-formed service name as a replacement for "sql*net". |
Jack Haverty | Jack Haverty | ||||||
| sql*net | 66 | tcp | Oracle SQL*NET | Jack Haverty | Jack Haverty | This entry is an alias to "sql-net". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| sql-net | 66 | udp | Oracle SQL*NET IANA assigned this well-formed service name as a replacement for "sql*net". |
Jack Haverty | Jack Haverty | ||||||
| sql*net | 66 | udp | Oracle SQL*NET | Jack Haverty | Jack Haverty | This entry is an alias to "sql-net". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| bootps | 67 | tcp | Bootstrap Protocol Server | Bill Croft | Bill Croft | RFC 951 | Defined TXT keys: None | ||||
| bootps | 67 | udp | Bootstrap Protocol Server | ||||||||
| bootpc | 68 | tcp | Bootstrap Protocol Client | Bill Croft | Bill Croft | ||||||
| bootpc | 68 | udp | Bootstrap Protocol Client | Bill Croft | Bill Croft | ||||||
| tftp | 69 | tcp | Trivial File Transfer | David Clark | David Clark | ||||||
| tftp | 69 | udp | Trivial File Transfer | David Clark | David Clark | ||||||
| gopher | 70 | tcp | Gopher | Mark McCahill | Mark McCahill | ||||||
| gopher | 70 | udp | Gopher | Mark McCahill | Mark McCahill | ||||||
| netrjs-1 | 71 | tcp | Remote Job Service | ||||||||
| netrjs-1 | 71 | udp | Remote Job Service | ||||||||
| netrjs-2 | 72 | tcp | Remote Job Service | ||||||||
| netrjs-2 | 72 | udp | Remote Job Service | ||||||||
| netrjs-3 | 73 | tcp | Remote Job Service | ||||||||
| netrjs-3 | 73 | udp | Remote Job Service | ||||||||
| netrjs-4 | 74 | tcp | Remote Job Service | Bob Braden | Bob Braden | ||||||
| netrjs-4 | 74 | udp | Remote Job Service | Bob Braden | Bob Braden | ||||||
| 75 | tcp | any private dial out service | Jon Postel | Jon Postel | |||||||
| 75 | udp | any private dial out service | Jon Postel | Jon Postel | |||||||
| deos | 76 | tcp | Distributed External Object Store | Robert Ullmann | Robert Ullmann | ||||||
| deos | 76 | udp | Distributed External Object Store | Robert Ullmann | Robert Ullmann | ||||||
| 77 | tcp | any private RJE service | Jon Postel | Jon Postel | |||||||
| 77 | udp | any private RJE service | Jon Postel | Jon Postel | |||||||
| vettcp | 78 | tcp | vettcp | Christopher Leong | Christopher Leong | ||||||
| vettcp | 78 | udp | vettcp | Christopher Leong | Christopher Leong | ||||||
| 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. | |||
| 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> | |||
| 81 | Unassigned | 2007-09-06 | |||||||||
| xfer | 82 | tcp | XFER Utility | Thomas M. Smith | Thomas M. Smith | ||||||
| xfer | 82 | udp | XFER Utility | Thomas M. Smith | Thomas M. Smith | ||||||
| mit-ml-dev | 83 | tcp | MIT ML Device | David Reed | David Reed | ||||||
| mit-ml-dev | 83 | udp | MIT ML Device | David Reed | David Reed | ||||||
| ctf | 84 | tcp | Common Trace Facility | Hugh Thomas | Hugh Thomas | ||||||
| ctf | 84 | udp | Common Trace Facility | Hugh Thomas | Hugh Thomas | ||||||
| mit-ml-dev | 85 | tcp | MIT ML Device | David Reed | David Reed | ||||||
| mit-ml-dev | 85 | udp | MIT ML Device | David Reed | David Reed | ||||||
| mfcobol | 86 | tcp | Micro Focus Cobol | Simon Edwards | Simon Edwards | ||||||
| mfcobol | 86 | udp | Micro Focus Cobol | Simon Edwards | Simon Edwards | ||||||
| 87 | tcp | any private terminal link | Jon Postel | Jon Postel | |||||||
| 87 | udp | any private terminal link | Jon Postel | Jon Postel | |||||||
| 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 | ||||
| su-mit-tg | 89 | tcp | SU/MIT Telnet Gateway | Mark Crispin | Mark Crispin | ||||||
| su-mit-tg | 89 | udp | SU/MIT Telnet Gateway | Mark Crispin | Mark Crispin | ||||||
| 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 | |||||
| mit-dov | 91 | tcp | MIT Dover Spooler | Eliot Moss | Eliot Moss | ||||||
| mit-dov | 91 | udp | MIT Dover Spooler | Eliot Moss | Eliot Moss | ||||||
| npp | 92 | tcp | Network Printing Protocol | Louis Mamakos | Louis Mamakos | ||||||
| npp | 92 | udp | Network Printing Protocol | Louis Mamakos | Louis Mamakos |