List of TCP and UDP port numbersetcservices, a service name database file on Unix like operating systems. This is a list of notable port numbers used by protocols of the transport layer of the Internet protocol suite for the establishment of host to host connectivity. Originally, port numbers were used by the Network Control Program NCP in the ARPANET for which two ports were required for half duplex transmission. Later, the Transmission Control Protocol TCP and the User Datagram Protocol UDP needed only one port for full duplex, bidirectional traffic. The even numbered ports were not used, and this resulted in some even numbers in the well known port number range being unassigned. The Stream Control Transmission Protocol SCTP and the Datagram Congestion Control Protocol DCCP also use port numbers. Download the free trial version below to get started. Doubleclick the downloaded file to install the software. This is a list of notable port numbers used by protocols of the transport layer of the Internet protocol suite for the establishment of hosttohost connectivity. Statistical Techniques Statistical Mechanics. Wiley Publishing. GB. They usually use port numbers that match the services of the corresponding TCP or UDP implementation, if they exist. The Internet Assigned Numbers Authority IANA is responsible for maintaining the official assignments of port numbers for specific uses. However, many unofficial uses of both well known and registered port numbers occur in practice. Similarly many of the official assignments refer to protocols that were never or are no longer in common use. This article lists port numbers and their associated protocols that have experienced significant uptake. Table legendedit  Official Port is registered with IANA for the application. Unofficial Port is not registered with IANA for the application. Multiple use Multiple applications are known to use this port. Well known portseditThe port numbers in the range from 0 to 1. They are used by system processes that provide widely used types of network services. On Unix like operating systems, a process must execute with superuser privileges to be able to bind a network socket to an IP address using one of the well known ports. Well known ports. Port. TCPUDPDescription. IANA status. 0NANAIn programming APIs not in communication between hosts, requests a system allocated dynamic port7NA0. Reserved. Reserved. Reserved. Official. TCPAssigned. TCP Port Service Multiplexer TCPMUX. Historic. Both TCP and UDP have been assigned to TCPMUX by IANA,5 but by design only TCP is specified. Official. Reserved. Reserved. Unassigned. Official. TCPUDPRemote job entry. Official. 6Reserved. Reserved. Unassigned. Official. 7TCPUDPEcho Protocol91. Official. 8Reserved. Reserved. Unassigned. Official. 9UDPDiscard Protocol1. Official. 9UDPWake on LAN1. Unofficial. 10. Reserved. Reserved. Unassigned. Official. 11. TCPUDPActive Users systat service1. Official. 12. Reserved. Reserved. Unassigned. Official. 13. TCPUDPDaytime Protocol1. Official. 14. Reserved. Reserved. Unassigned. Official. 15. TCPUDPPreviously netstat service51. Advance Bb5 Box Installer Youtube. Unofficial. 16. Reserved. Reserved. Unassigned. Official. 17. TCPUDPQuote of the Day QOTD1. Official. 18. TCPUDPMessage Send Protocol1. Official. 19. TCPUDPCharacter Generator Protocol CHARGEN2. Official. 20. Assigned. File Transfer Protocol FTP data transfer1. Official. 21. Assigned. File Transfer Protocol FTP control command1. Official. 22. UDPSecure Shell SSH,1. Official. 23. TCPAssigned. Telnet protocolunencrypted text communications1. Official. 25. TCPAssigned. Simple Mail Transfer Protocol SMTP,1. Official. 26. Reserved. Reserved. Unassigned. Official. 37. TCPUDPTime Protocol2. Official. 38. TCPUDPRoute Access Protocol RAP2. Official. 39. TCPUDPResource Location Protocol RLP2. Official. 40. Reserved. Reserved. Unassigned. Official. 42. TCPUDPHost Name Server Protocol2. Official. 43. TCPUDPWHOIS protocol2. Official. 49. TCPUDPTACACS Login Host protocol3. Official. 50. TCPUDPRemote Mail Checking Protocol3. Official. 51. Reserved. Official. 51. TCPUDPPreviously Interface Message Processor logical address managementcitation neededUnofficial. TCPUDPXerox Network Systems XNS Time ProtocolimportanceOfficial. TCPUDPDomain Name System DNS1. Official. 54. TCPUDPXerox Network Systems XNS clearinghouseimportanceOfficial. TCPUDPXerox Network Systems XNS authenticationimportanceOfficial. TCPUDPAny private terminal accessfurther explanation neededOfficial. TCPUDPXerox Network Systems XNS MailimportanceOfficial. Assigned. UDPBootstrap Protocol BOOTP server 1. Dynamic Host Configuration Protocol DHCPOfficial. Assigned. UDPBootstrap Protocol BOOTP client 1. Dynamic Host Configuration Protocol DHCPOfficial. Assigned. UDPTrivial File Transfer Protocol TFTP1. Official. 70. TCPUDPGopher protocol3. Official. 717. 4TCPUDPNETRJS protocol3. Official. 75. TCPUDPAny private dial out servicefurther explanation neededOfficial. TCPUDPAny private Remote job entryfurther explanation neededOfficial. TCPAssigned. Finger protocol1. Official. 80. UDP4. Hypertext Transfer Protocol HTTP1. Official. 80. UDPQUIC from Chromium for HTTPcitation neededUnofficial. NANAUnassigned. Official. TCPTor. Parkonion routingverification neededUnofficial. UDPTor. Park controlverification neededUnofficial. Any private terminal linkfurther explanation neededOfficial. TCPAssigned. Kerberos1. Official. 90. TCPUDPdnsix Do. D Network Security for Information Exchange Securit sic Attribute Token MapimportanceOfficial. TCPUDPPoint. Cast dotcom5third party source neededUnofficial. TCPWIP message protocolverification neededUnofficial. NANAUnassigned with known unauthorized usefurther explanation needed5Official. TCPUDPNIChost name. Official. 10. 2TCPUDPISO Transport Service Access Point TSAP Class 0 protocol 4. Official. 10. 4TCPUDPDigital Imaging and Communications in Medicine DICOM also port 1. Official. 10. 5TCPUDPCCSO Nameserver5. Official. 10. 7TCPUDPRemote User Telnet Service RTelnet5. Official. 10. 8TCPUDPIBM Systems Network Architecture SNA gateway access server. Official. 10. 9TCPUDPPost Office Protocol, version 2 POP25. Official. 11. 0TCPAssigned. Post Office Protocol, version 3 POP31. Official. 11. 1TCPUDPOpen Network Computing Remote Procedure Call ONC RPC, sometimes referred to as Sun RPCOfficial. TCPVirtual Router Redundancy Protocol VRRP5. Unofficial. 11. 3TCPIdent, authentication serviceidentification protocol,1. IRC servers to identify users. Official. 11. 3TCPAssigned. Authentication Service auth, the predecessor to identification protocol. Used to determine a users identity of a particular TCP connection. Official. 11. 4NANAUnassigned deprecated since June 2. Official. 11. 5TCPUDPSimple File Transfer Protocol1. Official. 11. 7TCPUDPUUCP Mapping Project path servicecitation neededOfficial. TCPUDPStructured Query Language SQL ServicesJargonOfficial. TCPAssigned. Network News Transfer Protocol NNTP,1. Official. 12. 3Assigned. UDPNetwork Time Protocol NTP, used for time synchronization1. Official. 12. 6TCPUDPFormerly Unisys Unitary Login, renamed by Unisys to NXEdit. Used by Unisys Programmers Workbench for Clearpath MCP, an IDE for Unisys MCP software development. Official. 13. 5TCPUDPDCEendpoint resolution. Official. 13. 5TCPUDPMicrosoft EPMAP End Point Mapper, also known as DCERPC Locator service,6. DHCP server, DNS server and WINS. Also used by DCOMOfficial. Assigned. UDPNet. BIOS Name Service, used for name registration and resolution6. Official. 13. 8TCPUDPNet. BIOS Datagram Service1. Official. 13. 9TCPAssigned. Net. BIOS Session Service6. Official. 14. 3TCPAssigned. Internet Message Access Protocol IMAP,1. Official. 15. 2TCPUDPBackground File Transfer Program BFTP6. Official. 15. 3TCPUDPSimple Gateway Monitoring Protocol SGMP, a protocol for remote inspection and alteration of gateway management information6. Official. 15. 6TCPUDPStructured Query Language SQL ServiceJargonOfficial. TCPUDPDistributed Mail System Protocol DMSP, sometimes referred to as Pcmail6. Official. 16. 1Assigned. UDPSimple Network Management Protocol SNMP6. Official. 16. 2TCPUDPSimple Network Management Protocol Trap SNMPTRAP6.