Service Name and Transport Protocol Port Number Registry
Last Updated
- 2026-11-05
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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| kpasswd | 464 | tcp | kpasswd | Greg Hudson | Greg Hudson | 2023-11-17 | |||||
| kpasswd | 464 | udp | kpasswd | Greg Hudson | Greg Hudson | 2023-11-17 | |||||
| nntps | 563 | tcp | nntp protocol over TLS/SSL (was snntp) | IESG | IETF Chair | 2018-07-06 | RFC 4642 | ||||
| nntps | 563 | udp | nntp protocol over TLS/SSL (was snntp) | IESG | IETF Chair | 2018-07-06 | RFC 4642 | ||||
| msl-lmd | 1464 | tcp | MSL License Manager IANA assigned this well-formed service name as a replacement for "msl_lmd". |
Matt Timmermans | Matt Timmermans | ||||||
| msl_lmd | 1464 | tcp | MSL License Manager | Matt Timmermans | Matt Timmermans | This entry is an alias to "msl-lmd". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| msl-lmd | 1464 | udp | MSL License Manager IANA assigned this well-formed service name as a replacement for "msl_lmd". |
Matt Timmermans | Matt Timmermans | ||||||
| msl_lmd | 1464 | udp | MSL License Manager | Matt Timmermans | Matt Timmermans | This entry is an alias to "msl-lmd". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| direcpc-si | 2464 | tcp | DirecPC SI | Doug Dillon | Doug Dillon | ||||||
| direcpc-si | 2464 | udp | DirecPC SI | Doug Dillon | Doug Dillon | ||||||
| edm-mgr-sync | 3464 | tcp | EDM MGR Sync | ||||||||
| edm-mgr-sync | 3464 | udp | EDM MGR Sync | ||||||||
| 4622-4645 | Unassigned | ||||||||||
| dots-signal | 4646 | tcp | Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel. | IESG | IETF Chair | 2020-01-16 | 2021-06-14 | RFC 8973; RFC 9132 | |||
| dots-signal | 4646 | udp | Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel. | IESG | IETF Chair | 2020-01-16 | 2021-06-14 | RFC 8973; RFC 9132 | |||
| 4647-4657 | Unassigned | ||||||||||
| quailnet | 5464 | tcp | Quail Networks Object Broker | Craig N. Bissell | Craig N. Bissell | 2006-04 | |||||
| quailnet | 5464 | udp | Quail Networks Object Broker | Craig N. Bissell | Craig N. Bissell | 2006-04 | |||||
| ieee11073-20701 | 6464 | tcp | Port assignment for medical device communication in accordance to IEEE 11073-20701 | David Gregorczyk | David Gregorczyk | 2017-03-02 | |||||
| ieee11073-20701 | 6464 | udp | Port assignment for medical device communication in accordance to IEEE 11073-20701 | David Gregorczyk | David Gregorczyk | 2017-03-02 | |||||
| 18464-18515 | Unassigned | ||||||||||
| 24387-24464 | Unassigned |
Contact Information
| Name | Organization | Contact URI | Last Updated |
|---|---|---|---|
| Craig N. Bissell | craig&quailnetworks.com | 2006-04 | |
| David Gregorczyk | david.gregorczyk&draeger.com | 2017-03-02 | |
| Doug Dillon | dillon&hns.com | ||
| Greg Hudson | ghudson&mit.edu | 2023-11-17 | |
| IESG | iesg&ietf.org | ||
| IETF Chair | IETF | chair&ietf.org | |
| Matt Timmermans |