Service Name and Transport Protocol Port Number Registry
- Last Updated
- 2025-10-30
- 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 | 
|---|---|---|---|---|---|---|---|---|---|---|---|
| print-srv | 170 | udp | Network PostScript | [Brian_Reid] | [Brian_Reid] | ||||||
| multiplex | 171 | tcp | Network Innovations Multiplex | ||||||||
| multiplex | 171 | udp | Network Innovations Multiplex | ||||||||
| 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. | |||||
| xyplex-mux | 173 | tcp | Xyplex | [Bob_Stewart] | [Bob_Stewart] | ||||||
| xyplex-mux | 173 | udp | Xyplex | [Bob_Stewart] | [Bob_Stewart] | ||||||
| mailq | 174 | tcp | MAILQ | [Rayan_Zachariassen] | [Rayan_Zachariassen] | ||||||
| mailq | 174 | udp | MAILQ | [Rayan_Zachariassen] | [Rayan_Zachariassen] | ||||||
| vmnet | 175 | tcp | VMNET | [Christopher_Tengi] | [Christopher_Tengi] | ||||||
| vmnet | 175 | udp | VMNET | [Christopher_Tengi] | [Christopher_Tengi] | ||||||
| genrad-mux | 176 | tcp | GENRAD-MUX | [Ron_Thornton] | [Ron_Thornton] | ||||||
| genrad-mux | 176 | udp | GENRAD-MUX | [Ron_Thornton] | [Ron_Thornton] | ||||||
| xdmcp | 177 | tcp | X Display Manager Control Protocol | [Robert_W_Scheifler] | [Robert_W_Scheifler] | ||||||
| xdmcp | 177 | udp | X Display Manager Control Protocol | [Robert_W_Scheifler] | [Robert_W_Scheifler] | ||||||
| nextstep | 178 | tcp | NextStep Window Server | [Leo_Hourvitz] | [Leo_Hourvitz] | ||||||
| nextstep | 178 | udp | NextStep Window Server | [Leo_Hourvitz] | [Leo_Hourvitz] | ||||||
| bgp | 179 | tcp | Border Gateway Protocol | [Kirk_Lougheed] | [Kirk_Lougheed] | ||||||
| bgp | 179 | udp | Border Gateway Protocol | [Kirk_Lougheed] | [Kirk_Lougheed] | ||||||
| bgp | 179 | sctp | BGP | [Randall_Stewart] | [Randall_Stewart] | 2022-02-07 | [RFC9260] | ||||
| ris | 180 | tcp | Intergraph | [Dave_Buehmann] | [Dave_Buehmann] | ||||||
| ris | 180 | udp | Intergraph | [Dave_Buehmann] | [Dave_Buehmann] | ||||||
| unify | 181 | tcp | Unify | [Daegis_Inc] | [Chris_Anderson] | 2012-07-31 | |||||
| unify | 181 | udp | Unify | [Daegis_Inc] | [Chris_Anderson] | 2012-07-31 | |||||
| audit | 182 | tcp | Unisys Audit SITP | [Gil_Greenbaum] | [Gil_Greenbaum] | ||||||
| audit | 182 | udp | Unisys Audit SITP | [Gil_Greenbaum] | [Gil_Greenbaum] | ||||||
| ocbinder | 183 | tcp | OCBinder | ||||||||
| ocbinder | 183 | udp | OCBinder | ||||||||
| ocserver | 184 | tcp | OCServer | [Jerrilynn_Okamura] | [Jerrilynn_Okamura] | ||||||
| ocserver | 184 | udp | OCServer | [Jerrilynn_Okamura] | [Jerrilynn_Okamura] | ||||||
| remote-kis | 185 | tcp | Remote-KIS | ||||||||
| remote-kis | 185 | udp | Remote-KIS | ||||||||
| kis | 186 | tcp | KIS Protocol | [Ralph_Droms] | [Ralph_Droms] | ||||||
| kis | 186 | udp | KIS Protocol | [Ralph_Droms] | [Ralph_Droms] | ||||||
| aci | 187 | tcp | Application Communication Interface | [Rick_Carlos] | [Rick_Carlos] | ||||||
| aci | 187 | udp | Application Communication Interface | [Rick_Carlos] | [Rick_Carlos] | ||||||
| mumps | 188 | tcp | Plus Five's MUMPS | [Hokey_Stenn] | [Hokey_Stenn] | ||||||
| mumps | 188 | udp | Plus Five's MUMPS | [Hokey_Stenn] | [Hokey_Stenn] | ||||||
| qft | 189 | tcp | Queued File Transport | [Wayne_Schroeder] | [Wayne_Schroeder] | ||||||
| qft | 189 | udp | Queued File Transport | [Wayne_Schroeder] | [Wayne_Schroeder] | ||||||
| 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] | ||||||
| prospero | 191 | tcp | Prospero Directory Service | [B_Clifford_Neuman] | [B_Clifford_Neuman] | ||||||
| prospero | 191 | udp | Prospero Directory Service | [B_Clifford_Neuman] | [B_Clifford_Neuman] | ||||||
| osu-nms | 192 | tcp | OSU Network Monitoring System | [Doug_Karl] | [Doug_Karl] | ||||||
| osu-nms | 192 | udp | OSU Network Monitoring System | [Doug_Karl] | [Doug_Karl] | ||||||
| srmp | 193 | tcp | Spider Remote Monitoring Protocol | [Ted_J_Socolofsky] | [Ted_J_Socolofsky] | ||||||
| srmp | 193 | udp | Spider Remote Monitoring Protocol | [Ted_J_Socolofsky] | [Ted_J_Socolofsky] | ||||||
| irc | 194 | tcp | Internet Relay Chat Protocol | [Jarkko_Oikarinen] | [Jarkko_Oikarinen] | ||||||
| irc | 194 | udp | Internet Relay Chat Protocol | [Jarkko_Oikarinen] | [Jarkko_Oikarinen] | ||||||
| dn6-nlm-aud | 195 | tcp | DNSIX Network Level Module Audit | ||||||||
| dn6-nlm-aud | 195 | udp | DNSIX Network Level Module Audit | ||||||||
| dn6-smm-red | 196 | tcp | DNSIX Session Mgt Module Audit Redir | [Lawrence_Lebahn] | [Lawrence_Lebahn] | ||||||
| dn6-smm-red | 196 | udp | DNSIX Session Mgt Module Audit Redir | [Lawrence_Lebahn] | [Lawrence_Lebahn] | ||||||
| dls | 197 | tcp | Directory Location Service | ||||||||
| dls | 197 | udp | Directory Location Service | ||||||||
| dls-mon | 198 | tcp | Directory Location Service Monitor | [Scott_Bellew] | [Scott_Bellew] | ||||||
| dls-mon | 198 | udp | Directory Location Service Monitor | [Scott_Bellew] | [Scott_Bellew] | ||||||
| smux | 199 | tcp | SMUX | [Marshall_Rose] | [Marshall_Rose] | ||||||
| smux | 199 | udp | SMUX | [Marshall_Rose] | [Marshall_Rose] | ||||||
| at-rtmp | 201 | tcp | AppleTalk Routing Maintenance | ||||||||
| at-rtmp | 201 | udp | AppleTalk Routing Maintenance | ||||||||
| z39-50 | 210 | tcp | ANSI Z39.50 IANA assigned this well-formed service name as a replacement for "z39.50". | [Mark_H_Needleman] | [Mark_H_Needleman] | ||||||
| z39.50 | 210 | tcp | ANSI Z39.50 | [Mark_H_Needleman] | [Mark_H_Needleman] | This entry is an alias to "z39-50". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| z39-50 | 210 | udp | ANSI Z39.50 IANA assigned this well-formed service name as a replacement for "z39.50". | [Mark_H_Needleman] | [Mark_H_Needleman] | ||||||
| z39.50 | 210 | udp | ANSI Z39.50 | [Mark_H_Needleman] | [Mark_H_Needleman] | This entry is an alias to "z39-50". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| 914c-g | 211 | tcp | Texas Instruments 914C/G Terminal IANA assigned this well-formed service name as a replacement for "914c/g". | [Bill_Harrell] | [Bill_Harrell] | ||||||
| 914c/g | 211 | tcp | Texas Instruments 914C/G Terminal | [Bill_Harrell] | [Bill_Harrell] | This entry is an alias to "914c-g". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| 914c-g | 211 | udp | Texas Instruments 914C/G Terminal IANA assigned this well-formed service name as a replacement for "914c/g". | [Bill_Harrell] | [Bill_Harrell] | ||||||
| 914c/g | 211 | udp | Texas Instruments 914C/G Terminal | [Bill_Harrell] | [Bill_Harrell] | This entry is an alias to "914c-g". This entry is now historic, not usable for use with many common service discovery mechanisms. | |||||
| anet | 212 | tcp | ATEXSSTR | [Jim_Taylor] | [Jim_Taylor] | ||||||
| anet | 212 | udp | ATEXSSTR | [Jim_Taylor] | [Jim_Taylor] | ||||||
| ipx | 213 | tcp | IPX | [Don_Provan] | [Don_Provan] | ||||||
| ipx | 213 | udp | IPX | [Don_Provan] | [Don_Provan] | ||||||
| vmpwscs | 214 | tcp | VM PWSCS | [Dan_Shia] | [Dan_Shia] | ||||||
| vmpwscs | 214 | udp | VM PWSCS | [Dan_Shia] | [Dan_Shia] | ||||||
| softpc | 215 | tcp | Insignia Solutions | [Martyn_Thomas] | [Martyn_Thomas] | ||||||
| softpc | 215 | udp | Insignia Solutions | [Martyn_Thomas] | [Martyn_Thomas] | ||||||
| CAIlic | 216 | tcp | Computer Associates Int'l License Server | [Chuck_Spitz] | [Chuck_Spitz] | ||||||
| CAIlic | 216 | udp | Computer Associates Int'l License Server | [Chuck_Spitz] | [Chuck_Spitz] | ||||||
| dbase | 217 | tcp | dBASE Unix | [Don_Gibson] | [Don_Gibson] | ||||||
| dbase | 217 | udp | dBASE Unix | [Don_Gibson] | [Don_Gibson] | ||||||
| mpp | 218 | tcp | Netix Message Posting Protocol | [Shannon_Yeh] | [Shannon_Yeh] | ||||||
| mpp | 218 | udp | Netix Message Posting Protocol | [Shannon_Yeh] | [Shannon_Yeh] | ||||||
| uarps | 219 | tcp | Unisys ARPs | [Ashok_Marwaha] | [Ashok_Marwaha] | ||||||
| uarps | 219 | udp | Unisys ARPs | [Ashok_Marwaha] | [Ashok_Marwaha] | ||||||
| fln-spx | 221 | tcp | Berkeley rlogind with SPX auth | ||||||||
| fln-spx | 221 | udp | Berkeley rlogind with SPX auth | ||||||||
| 225-241 | Reserved | 2024-12-20 | [RFC1060] | ||||||||
| 249-255 | Reserved | 2024-12-20 | [RFC1060] | ||||||||
| nsiiops | 261 | tcp | IIOP Name Service over TLS/SSL | [Jeff_Stewart] | [Jeff_Stewart] | ||||||
| nsiiops | 261 | udp | IIOP Name Service over TLS/SSL | [Jeff_Stewart] | [Jeff_Stewart] | ||||||
| gist | 270 | udp | Q-mode encapsulation for GIST messages | [RFC5971] | |||||||
| pt-tls | 271 | tcp | IETF Network Endpoint Assessment (NEA) Posture Transport Protocol over TLS (PT-TLS) | [IESG] | [IETF_Chair] | 2012-07-31 | [RFC6876] | ||||
| 271 | udp | Reserved | |||||||||
| personal-link | 281 | tcp | Personal Link | [Dan_Cummings] | [Dan_Cummings] | ||||||
| personal-link | 281 | udp | Personal Link | [Dan_Cummings] | [Dan_Cummings] | ||||||
| tacacss | 300 | tcp | TLS Secure Login Host Protocol (TACACSS) | [IESG] | [IETF_Chair] | 2025-07-15 | [RFC-ietf-opsawg-tacacs-tls13-24] | ||||
| 301-307 | Unassigned |