Service Name and Transport Protocol Port Number Registry
- Last Updated
- 2025-12-15
- 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]
- Available Formats
-

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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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 | [RFC9260] | ||||
| 12 | tcp | Unassigned | |||||||||
| 12 | 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 | tcp | File Transfer Protocol [Control] | [Jon_Postel] | [Jon_Postel] | [RFC959] | Defined TXT keys: u=<username> p=<password> path=<path> | ||||
| ftp | 21 | udp | File Transfer Protocol [Control] | [Jon_Postel] | [Jon_Postel] | [RFC959] | Defined TXT keys: u=<username> p=<password> path=<path> | ||||
| ftp | 21 | sctp | FTP | [Randall_Stewart] | [Randall_Stewart] | 2022-02-07 | [RFC9260] | Defined TXT keys: u=<username> p=<password> path=<path> | |||
| ssh | 22 | tcp | The Secure Shell (SSH) Protocol | [RFC4251] | Defined TXT keys: u=<username> p=<password> | ||||||
| ssh | 22 | udp | The Secure Shell (SSH) Protocol | [RFC4251] | Defined TXT keys: u=<username> p=<password> | ||||||
| ssh | 22 | sctp | SSH | [Randall_Stewart] | [Randall_Stewart] | 2022-02-07 | [RFC9260] | Defined TXT keys: u=<username> p=<password> | |||
| telnet | 23 | tcp | Telnet | [Jon_Postel] | [Jon_Postel] | [RFC854] | Defined TXT keys: u=<username> p=<password> | ||||
| telnet | 23 | udp | Telnet | [Jon_Postel] | [Jon_Postel] | [RFC854] | Defined TXT keys: u=<username> p=<password> | ||||
| 24 | tcp | any private mail system | [Rick_Adams] | [Rick_Adams] | |||||||
| 24 | udp | any private mail system | [Rick_Adams] | [Rick_Adams] | |||||||
| 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] | ||||
| 26 | tcp | Unassigned | |||||||||
| 26 | udp | Unassigned | |||||||||
| nsw-fe | 27 | tcp | NSW User System FE | [Robert_Thomas] | [Robert_Thomas] | ||||||
| nsw-fe | 27 | udp | NSW User System FE | [Robert_Thomas] | [Robert_Thomas] | ||||||
| 28 | tcp | Unassigned | |||||||||
| 28 | udp | Unassigned | |||||||||
| msg-icp | 29 | tcp | MSG ICP | [Robert_Thomas] | [Robert_Thomas] | ||||||
| msg-icp | 29 | udp | MSG ICP | [Robert_Thomas] | [Robert_Thomas] | ||||||
| 32 | tcp | Unassigned | |||||||||
| 32 | udp | Unassigned | |||||||||
| name | 42 | tcp | Host Name Server | ||||||||
| name | 42 | udp | Host Name Server | ||||||||
| nameserver | 42 | tcp | Host Name Server | ||||||||
| nameserver | 42 | udp | Host Name Server | ||||||||
| 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. | ||||||||
| xns-time | 52 | tcp | XNS Time Protocol | [Susie_Armstrong] | [Susie_Armstrong] | ||||||
| xns-time | 52 | udp | XNS Time Protocol | [Susie_Armstrong] | [Susie_Armstrong] | ||||||
| 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] | ||||||
| netrjs-2 | 72 | tcp | Remote Job Service | ||||||||
| netrjs-2 | 72 | udp | Remote Job Service | ||||||||
| http | 80 | sctp | HTTP | [Randall_Stewart] | [Randall_Stewart] | 2022-02-07 | [RFC9260] | Defined TXT keys: u=<username> p=<password> path=<path to document> | |||
| xfer | 82 | tcp | XFER Utility | [Thomas_M_Smith] | [Thomas_M_Smith] | ||||||
| xfer | 82 | udp | XFER Utility | [Thomas_M_Smith] | [Thomas_M_Smith] | ||||||
| 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] | ||||
| npp | 92 | tcp | Network Printing Protocol | [Louis_Mamakos] | [Louis_Mamakos] | ||||||
| npp | 92 | udp | Network Printing Protocol | [Louis_Mamakos] | [Louis_Mamakos] | ||||||
| iso-tsap | 102 | tcp | ISO-TSAP Class 0 | [Marshall_Rose] | [Marshall_Rose] | ||||||
| iso-tsap | 102 | udp | ISO-TSAP Class 0 | [Marshall_Rose] | [Marshall_Rose] | ||||||
| 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] | ||||||
| mcidas | 112 | tcp | McIDAS Data Transmission Protocol | [Glenn_Davis] | [Glenn_Davis] | ||||||
| mcidas | 112 | udp | McIDAS Data Transmission Protocol | [Glenn_Davis] | [Glenn_Davis] | ||||||
| 114 | unassigned | Deprecated June 2004 | |||||||||
| cfdptkt | 120 | tcp | CFDPTKT | [John_Ioannidis] | [John_Ioannidis] | ||||||
| cfdptkt | 120 | udp | CFDPTKT | [John_Ioannidis] | [John_Ioannidis] | ||||||
| erpc | 121 | tcp | Encore Expedited Remote Pro.Call | [Jack_ONeil] | [Jack_ONeil] | ||||||
| erpc | 121 | udp | Encore Expedited Remote Pro.Call | [Jack_ONeil] | [Jack_ONeil] | ||||||
| smakynet | 122 | tcp | SMAKYNET | [Pierre_Arnaud] | [Pierre_Arnaud] | ||||||
| smakynet | 122 | udp | SMAKYNET | [Pierre_Arnaud] | [Pierre_Arnaud] | ||||||
| ntp | 123 | tcp | Network Time Protocol | [Dave_Mills] | [Dave_Mills] | [RFC5905] | |||||
| ntp | 123 | udp | Network Time Protocol | [Dave_Mills] | [Dave_Mills] | [RFC5905] | |||||
| ansatrader | 124 | tcp | ANSA REX Trader | [Nicola_J_Howarth] | [Nicola_J_Howarth] | ||||||
| ansatrader | 124 | udp | ANSA REX Trader | [Nicola_J_Howarth] | [Nicola_J_Howarth] | ||||||
| locus-map | 125 | tcp | Locus PC-Interface Net Map Ser | [Eric_Peterson] | [Eric_Peterson] | ||||||
| locus-map | 125 | udp | Locus PC-Interface Net Map Ser | [Eric_Peterson] | [Eric_Peterson] | ||||||
| nxedit | 126 | tcp | NXEdit | [Don_Payette] | [Don_Payette] | Port 126 Previously assigned to application below unitary 126/tcp Unisys Unitary Login unitary 126/udp Unisys Unitary Login <feil&kronos.nisd.cam.unisys.com> Port 126 Previously assigned to application above | |||||
| nxedit | 126 | udp | NXEdit | [Don_Payette] | [Don_Payette] | Port 126 Previously assigned to application below unitary 126/tcp Unisys Unitary Login unitary 126/udp Unisys Unitary Login <feil&kronos.nisd.cam.unisys.com> Port 126 Previously assigned to application above | |||||
| locus-con | 127 | tcp | Locus PC-Interface Conn Server | [Eric_Peterson] | [Eric_Peterson] | ||||||
| locus-con | 127 | udp | Locus PC-Interface Conn Server | [Eric_Peterson] | [Eric_Peterson] | ||||||
| gss-xlicen | 128 | tcp | GSS X License Verification | [John_Light] | [John_Light] | ||||||
| gss-xlicen | 128 | udp | GSS X License Verification | [John_Light] | [John_Light] | ||||||
| pwdgen | 129 | tcp | Password Generator Protocol | [Frank_J_Wacho] | [Frank_J_Wacho] | ||||||
| pwdgen | 129 | udp | Password Generator Protocol | [Frank_J_Wacho] | [Frank_J_Wacho] | ||||||
| cisco-sys | 132 | tcp | cisco SYSMAINT | ||||||||
| cisco-sys | 132 | udp | cisco SYSMAINT | ||||||||
| statsrv | 133 | tcp | Statistics Service | [Dave_Mills_2] | [Dave_Mills_2] | ||||||
| statsrv | 133 | udp | Statistics Service | [Dave_Mills_2] | [Dave_Mills_2] | ||||||
| bl-idm | 142 | tcp | Britton-Lee IDM | [Susie_Snitzer] | [Susie_Snitzer] | ||||||
| bl-idm | 142 | udp | Britton-Lee IDM | [Susie_Snitzer] | [Susie_Snitzer] | ||||||
| aed-512 | 149 | tcp | AED 512 Emulation Service | [Albert_G_Broscius] | [Albert_G_Broscius] | ||||||
| aed-512 | 149 | udp | AED 512 Emulation Service | [Albert_G_Broscius] | [Albert_G_Broscius] | ||||||
| bftp | 152 | tcp | Background File Transfer Program | [Annette_DeSchon] | [Annette_DeSchon] | ||||||
| bftp | 152 | udp | Background File Transfer Program | [Annette_DeSchon] | [Annette_DeSchon] | ||||||
| snmptrap | 162 | tcp | SNMPTRAP | [Marshall_Rose] | [Marshall_Rose] | ||||||
| snmptrap | 162 | udp | SNMPTRAP | [Marshall_Rose] | [Marshall_Rose] | ||||||
| xns-courier | 165 | tcp | Xerox | [Susie_Armstrong_2] | [Susie_Armstrong_2] | ||||||
| xns-courier | 165 | udp | Xerox | [Susie_Armstrong_2] | [Susie_Armstrong_2] | ||||||
| cl-1 | 172 | tcp | Network Innovations CL/1 IANA assigned this well-formed service name as a replacement for "cl/1". |
[Kevin_DeVault] | [Kevin_DeVault] | ||||||
| cl/1 | 172 | tcp | Network Innovations CL/1 | [Kevin_DeVault] | [Kevin_DeVault] | This entry is an alias to "cl-1". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| cl-1 | 172 | udp | Network Innovations CL/1 IANA assigned this well-formed service name as a replacement for "cl/1". |
[Kevin_DeVault] | [Kevin_DeVault] | ||||||
| cl/1 | 172 | udp | Network Innovations CL/1 | [Kevin_DeVault] | [Kevin_DeVault] | This entry is an alias to "cl-1". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| bgp | 179 | sctp | BGP | [Randall_Stewart] | [Randall_Stewart] | 2022-02-07 | [RFC9260] |