This is a list of Internet socket 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. 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.
Table legend
| Use | Description | Color |
|---|---|---|
| Official | Port is registered with IANA for the application | White |
| Unofficial | Port is not registered with IANA for the application | Blue |
| Multiple use | Multiple applications are known to use this port. | Khaki |
Well-known ports
The port numbers in the range from 0 to 1023 are the well-known ports or system ports. 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.
| Port | TCP | UDP | Description | Status |
|---|---|---|---|---|
| 0 | TCP | Programming technique for specifying system-allocated (dynamic) ports | Unofficial | |
| 0 | UDP | Reserved | Official | |
| 1 | TCP | UDP | TCP Port Service Multiplexer (TCPMUX) | Official |
| 2 | TCP | UDP | CompressNET Management Utility | Official |
| 3 | TCP | UDP | CompressNET Compression Process | Official |
| 4 | TCP | UDP | Unassigned | Official |
| 5 | TCP | UDP | Remote Job Entry | Official |
| 6 | TCP | UDP | Unassigned | Official |
| 7 | TCP | UDP | Echo Protocol | Official |
| 8 | TCP | UDP | Unassigned | Official |
| 9 | TCP | UDP | Discard Protocol | Official |
| 9 | UDP | Wake-on-LAN | Unofficial | |
| 10 | TCP | UDP | Unassigned | Official |
| 11 | TCP | UDP | Active Users (systat service) | Official |
| 12 | TCP | UDP | Unassigned | Official |
| 13 | TCP | UDP | Daytime Protocol (RFC 867) | Official |
| 14 | TCP | UDP | Unassigned | Official |
| 15 | TCP | UDP | Previously netstat service | Unofficial |
| 16 | TCP | UDP | Unassigned | Official |
| 17 | TCP | UDP | Quote of the Day | Official |
| 18 | TCP | UDP | Message Send Protocol | Unofficial |
| 19 | TCP | UDP | Character Generator Protocol (CHARGEN) | Unofficial |
| 20 | TCP | UDP | FTP data transfer | Official |
| 21 | TCP, SCTP | UDP | FTP control (command) | Official |
| 22 | TCP, SCTP | UDP | Secure Shell (SSH)—used for secure logins, file transfers (scp, sftp) and port forwarding | Official |
| 23 | TCP | UDP | Telnet protocol—unencrypted text communications | Official |
| 24 | TCP | UDP | Priv-mail : any private mail system. | Official |
| 25 | TCP | UDP | Simple Mail Transfer Protocol (SMTP)—used for e-mail routing between mail servers | Official |
| 26 | TCP | UDP | Unassigned | Official |
| 27 | TCP | UDP | NSW User System FE | Official |
| 29 | TCP | UDP | MSG ICP | Official |
| 33 | TCP | UDP | Display Support Protocol | Official |
| 35 | TCP | UDP | Any private printer server protocol | Official |
| 37 | TCP | UDP | TIME protocol | Official |
| 39 | TCP | UDP | Resource Location Protocol (RLP)—used for determining the location of higher level services from hosts on a network | Official |
| 40 | TCP | UDP | Unassigned | Official |
| 42 | TCP | UDP | ARPA Host Name Server Protocol | Official |
| 42 | TCP | UDP | Windows Internet Name Service | Unofficial |
| 43 | TCP | UDP | WHOIS protocol | Official |
| 47 | TCP | UDP | NI FTP | Official |
| 49 | TCP | UDP | TACACS+ Login Host protocol | Official |
| 50 | TCP | UDP | ESP | Official |
| 51 | TCP | UDP | IMP Logical Address Maintenance | Official |
| 52 | TCP | UDP | XNS (Xerox Network Systems) Time Protocol | Official |
| 53 | TCP | UDP | Domain Name System (DNS) | Official |
| 54 | TCP | UDP | XNS (Xerox Network Systems) Clearinghouse | Official |
| 55 | TCP | UDP | ISI Graphics Language (ISI-GL) | Official |
| 56 | TCP | UDP | XNS (Xerox Network Systems) Authentication | Official |
| 56 | TCP | UDP | Route Access Protocol (RAP) | Unofficial |
| 57 | TCP | UDP | any private terminal access | Official |
| 58 | TCP | UDP | XNS (Xerox Network Systems) Mail | Official |
| 64 | TCP | UDP | CI (Travelport) (formerly Covia) Comms Integrator | Official |
| 67 | TCP | UDP | Bootstrap Protocol (BOOTP) Server; also used by Dynamic Host Configuration Protocol (DHCP) | Official |
| 68 | TCP | UDP | Bootstrap Protocol (BOOTP) Client; also used by Dynamic Host Configuration Protocol (DHCP) | Official |
| 69 | TCP | UDP | Trivial File Transfer Protocol (TFTP) | Official |
| 70 | TCP | UDP | Gopher protocol | Official |
| 71 | TCP | UDP | NETRJS protocol | Official |
| 72 | TCP | UDP | NETRJS protocol | Official |
| 73 | TCP | UDP | NETRJS protocol | Official |
| 74 | TCP | UDP | NETRJS protocol | Official |
| 77 | TCP | UDP | Any private Remote Job Entry | Official |
| 79 | TCP | UDP | Finger protocol | Official |
| 80 | TCP, SCTP | UDP | Hypertext Transfer Protocol (HTTP) | Official |
| 80 | UDP | QUIC (from Chromium) for HTTP | Unofficial | |
| 81 | TCP | Torpark—Onion routing | Unofficial | |
| 82 | UDP | Torpark—Control | Unofficial | |
| 88 | TCP | UDP | Kerberos—authentication system | Official |
| 90 | TCP | UDP | dnsix (DoD Network Security for Information Exchange) Security Attribute Token Map | Official |
| 90 | TCP | UDP | PointCast (dotcom) | Unofficial |
| 99 | TCP | WIP Message protocol | Unofficial | |
| 100 | UDP | CyberGate RAT protocol | Unofficial | |
| 101 | TCP | UDP | NIC host name | Official |
| 102 | TCP | UDP | ISO-TSAP (Transport Service Access Point) Class 0 protocol; also used by Digital Equipment Corporation DECnet (Phase V+) over TCP/IP | Official |
| 104 | TCP | UDP | ACR/NEMA Digital Imaging and Communications in Medicine (DICOM) | Official |
| 105 | TCP | UDP | CCSO Nameserver Protocol (Qi/Ph) | Official |
| 107 | TCP | UDP | Remote TELNET Service protocol | Official |
| 108 | TCP | UDP | SNA Gateway Access Server | Official |
| 109 | TCP | UDP | Post Office Protocol v2 (POP2) | Official |
| 110 | TCP | UDP | Post Office Protocol v3 (POP3) | Official |
| 111 | TCP | UDP | ONC RPC (Sun RPC) | Official |
| 113 | TCP | Ident—Authentication Service/Identification Protocol, used by IRC servers to identify users | Official | |
| 113 | UDP | Authentication Service (auth) | Official | |
| 115 | TCP | Simple File Transfer Protocol | Official | |
| 117 | STD | UUCP Path Service | Official | |
| 118 | TCP | UDP | SQL (Structured Query Language) Services | Official |
| 119 | TCP | Network News Transfer Protocol (NNTP)—retrieval of newsgroup messages | Official | |
| 123 | TCP | UDP | Network Time Protocol (NTP)—used for time synchronization | Official |
| 126 | TCP | UDP | Formerly Unisys Unitary Login, renamed by Unisys to NXEdit. Used by Unisys Programmer's Workbench for Clearpath MCP, an IDE for Unisys MCP software development | Official |
| 135 | TCP | UDP | DCE endpoint resolution | Official |
| 135 | TCP | UDP | Microsoft EPMAP (End Point Mapper), also known as DCE/RPC Locator service, used to remotely manage services including DHCP server, DNS server and WINS. Also used by DCOM | Unofficial |
| 137 | TCP | UDP | NetBIOS NetBIOS Name Service | Official |
| 138 | TCP | UDP | NetBIOS NetBIOS Datagram Service | Official |
| 139 | TCP | UDP | NetBIOS NetBIOS Session Service | Official |
| 143 | TCP | Internet Message Access Protocol (IMAP)—management of email messages | Official | |
| 152 | TCP | UDP | Background File Transfer Program (BFTP) | Official |
| 153 | TCP | UDP | SGMP, Simple Gateway Monitoring Protocol | Official |
| 156 | TCP | UDP | SQL Service | Official |
| 158 | TCP | UDP | DMSP, Distributed Mail Service Protocol | Unofficial |
| 161 | UDP | Simple Network Management Protocol (SNMP) | Official | |
| 162 | TCP | UDP | Simple Network Management Protocol Trap (SNMPTRAP) | Official |
| 170 | TCP | Print-srv, Network PostScript | Official | |
| 175 | TCP | VMNET (IBM z/VM, z/OS & z/VSE—Network Job Entry (NJE)) | Official | |
| 177 | TCP | UDP | X Display Manager Control Protocol (XDMCP) | Official |
| 179 | TCP | BGP (Border Gateway Protocol) | Official | |
| 194 | TCP | UDP | Internet Relay Chat (IRC) | Official |
| 199 | TCP | UDP | SMUX, SNMP Unix Multiplexer | Official |
| 201 | TCP | UDP | AppleTalk Routing Maintenance | Official |
| 209 | TCP | UDP | The Quick Mail Transfer Protocol | Official |
| 210 | TCP | UDP | ANSI Z39.50 | Official |
| 213 | TCP | UDP | Internetwork Packet Exchange (IPX) | Official |
| 218 | TCP | UDP | Message posting protocol (MPP) | Official |
| 220 | TCP | UDP | Internet Message Access Protocol (IMAP), version 3 | Official |
| 259 | TCP | UDP | ESRO, Efficient Short Remote Operations | Official |
| 262 | TCP | UDP | Arcisdms | Official |
| 264 | TCP | UDP | BGMP, Border Gateway Multicast Protocol | Official |
| 280 | TCP | UDP | http-mgmt | Official |
| 300 | TCP | ThinLinc Web Access | Unofficial | |
| 308 | TCP | Novastor Online Backup | Official | |
| 311 | TCP | Mac OS X Server Admin (officially AppleShare IP Web administration) | Official | |
| 318 | TCP | UDP | PKIX TSP, Time Stamp Protocol | Official |
| 319 | UDP | Precision Time Protocol (PTP) event messages | Official | |
| 320 | UDP | Precision Time Protocol (PTP) general messages | Official | |
| 350 | TCP | UDP | MATIP-Type A, Mapping of Airline Traffic over Internet Protocol | Official |
| 351 | TCP | UDP | MATIP-Type B, Mapping of Airline Traffic over Internet Protocol | Official |
| 356 | TCP | UDP | cloanto-net-1 (used by Cloanto Amiga Explorer and VMs) | Official |
| 366 | TCP | UDP | ODMR, On-Demand Mail Relay | Official |
| 369 | TCP | UDP | Rpc2portmap | Official |
| 370 | TCP | codaauth2—Coda authentication server | Official | |
| 370 | UDP | codaauth2—Coda authentication server | Official | |
| 370 | UDP | securecast1—Outgoing packets to NAI's SecureCast servers As of 2000 | Unofficial | |
| 371 | TCP | UDP | ClearCase albd | Official |
| 383 | TCP | UDP | HP data alarm manager | Official |
| 384 | TCP | UDP | A Remote Network Server System | Official |
| 387 | TCP | UDP | AURP, AppleTalk Update-based Routing Protocol | Official |
| 389 | TCP | UDP | Lightweight Directory Access Protocol (LDAP) | Official |
| 399 | TCP | UDP | Digital Equipment Corporation DECnet (Phase V+) over TCP/IP | Official |
| 401 | TCP | UDP | UPS Uninterruptible Power Supply | Official |
| 427 | TCP | UDP | Service Location Protocol (SLP) | Official |
| 433 | TCP | UDP | NNSP, part of Network News Transfer Protocol | Official |
| 434 | TCP | UDP | Mobile IP Agent (RFC 5944) | Official |
| 443 | TCP, SCTP | UDP | Hypertext Transfer Protocol over TLS/SSL (HTTPS) | Official |
| 443 | UDP | QUIC (from Chromium) for HTTPS | Unofficial | |
| 444 | TCP | UDP | SNPP, Simple Network Paging Protocol (RFC 1568) | Official |
| 445 | TCP | Microsoft-DS Active Directory, Windows shares | Official | |
| 445 | TCP | Microsoft-DS SMB file sharing | Official | |
| 464 | TCP | UDP | Kerberos Change/Set password | Official |
| 465 | TCP | URL Rendezvous Directory for SSM (Cisco protocol) | Official | |
| 465 | TCP | Simple Mail Transfer Protocol over TLS/SSL (SMTPS) | Unofficial | |
| 475 | TCP | UDP | tcpnethaspsrv (Aladdin Knowledge Systems Hasp services, TCP/IP version) | Official |
| 491 | TCP | GO-Global remote access and application publishing software | Unofficial | |
| 497 | TCP | Dantz Retrospect | Official | |
| 500 | TCP | UDP | Internet Security Association and Key Management Protocol (ISAKMP) | Official |
| 502 | TCP | UDP | Modbus Protocol | Official |
| 504 | TCP | UDP | Citadel—multiservice protocol for dedicated clients for the Citadel groupware system | Official |
| 510 | TCP | UDP | FirstClass Protocol (FCP), used by FirstClass client/server groupware system | Official |
| 512 | TCP | Rexec, Remote Process Execution | Official | |
| 512 | UDP | comsat, together with biff | Official | |
| 513 | TCP | rlogin | Official | |
| 513 | UDP | Who | Official | |
| 514 | TCP | Shell—used to execute non-interactive commands on a remote system (Remote Shell, rsh, remsh) | Official | |
| 514 | UDP | Syslog—used for system logging | Official | |
| 515 | TCP | Line Printer Daemon—print service | Official | |
| 517 | UDP | Talk | Official | |
| 518 | UDP | NTalk | Official | |
| 520 | TCP | efs, extended file name server | Official | |
| 520 | UDP | Routing Information Protocol (RIP) | Official | |
| 521 | UDP | Routing Information Protocol Next Generation (RIPng) | Official | |
| 524 | TCP | UDP | NetWare Core Protocol (NCP) is used for a variety things such as access to primary NetWare server resources, Time Synchronization, etc. | Official |
| 525 | UDP | Timed, Timeserver | Official | |
| 530 | TCP | UDP | RPC | Official |
| 531 | TCP | UDP | AOL Instant Messenger | Unofficial |
| 532 | TCP | netnews | Official | |
| 533 | UDP | netwall, For Emergency Broadcasts | Official | |
| 540 | TCP | UUCP (Unix-to-Unix Copy Protocol) | Official | |
| 542 | TCP | UDP | commerce (Commerce Applications) | Official |
| 543 | TCP | klogin, Kerberos login | Official | |
| 544 | TCP | kshell, Kerberos Remote shell | Official | |
| 545 | TCP | OSIsoft PI (VMS), OSISoft PI Server Client Access | Unofficial | |
| 546 | TCP | UDP | DHCPv6 client | Official |
| 547 | TCP | UDP | DHCPv6 server | Official |
| 548 | TCP | Apple Filing Protocol (AFP) over TCP | Official | |
| 550 | TCP | UDP | new-rwho, new-who | Official |
| 554 | TCP | UDP | Real Time Streaming Protocol (RTSP) | Official |
| 556 | TCP | Remotefs, RFS, rfs_server | Official | |
| 560 | UDP | rmonitor, Remote Monitor | Official | |
| 561 | UDP | monitor | Official | |
| 563 | TCP | UDP | NNTP over TLS/SSL (NNTPS) | Official |
| 564 | TCP | Plan9 | Unofficial | |
| 587 | TCP | e-mail message submission (SMTP) | Official | |
| 591 | TCP | FileMaker 6.0 (and later) Web Sharing (HTTP Alternate, also see port 80) | Official | |
| 593 | TCP | UDP | HTTP RPC Ep Map, Remote procedure call over Hypertext Transfer Protocol, often used by Distributed Component Object Model services and Microsoft Exchange Server | Official |
| 604 | TCP | TUNNEL profile, a protocol for BEEP peers to form an application layer tunnel | Official | |
| 623 | UDP | ASF Remote Management and Control Protocol (ASF-RMCP) | Official | |
| 625 | TCP | Open Directory Proxy (ODProxy) | Unofficial | |
| 631 | TCP | UDP | Internet Printing Protocol (IPP) | Official |
| 631 | TCP | UDP | Common Unix Printing System (CUPS) administration console (extension to IPP) | Unofficial |
| 635 | TCP | UDP | RLZ DBase | Official |
| 636 | TCP | UDP | Lightweight Directory Access Protocol over TLS/SSL (LDAPS) | Official |
| 639 | TCP | UDP | MSDP, Multicast Source Discovery Protocol | Official |
| 641 | TCP | UDP | SupportSoft Nexus Remote Command (control/listening): A proxy gateway connecting remote control traffic | Official |
| 643 | TCP | UDP | SANity | Official |
| 646 | TCP | UDP | LDP, Label Distribution Protocol, a routing protocol used in MPLS networks | Official |
| 647 | TCP | DHCP Failover protocol | Official | |
| 648 | TCP | RRP (Registry Registrar Protocol) | Official | |
| 651 | TCP | UDP | IEEE-MMS | Official |
| 653 | TCP | UDP | SupportSoft Nexus Remote Command (data): A proxy gateway connecting remote control traffic | Official |
| 654 | TCP | Media Management System (MMS) Media Management Protocol (MMP) | Official | |
| 655 | TCP | UDP | Tinc VPN daemon | Unofficial |
| 657 | TCP | UDP | IBM RMC (Remote monitoring and Control) protocol, used by System p5 AIX Integrated Virtualization Manager (IVM) and Hardware Management Console to connect managed logical partitions (LPAR) to enable dynamic partition reconfiguration | Official |
| 660 | TCP | Mac OS X Server administration | Official | |
| 666 | TCP | UDP | Doom, first online first-person shooter | Official |
| 666 | TCP | airserv-ng, aircrack-ng's server for remote-controlling wireless devices | Unofficial | |
| 674 | TCP | ACAP (Application Configuration Access Protocol) | Official | |
| 688 | TCP | UDP | REALM-RUSD (ApplianceWare Server Appliance Management Protocol) | Official |
| 690 | TCP | UDP | VATP (Velneo Application Transfer Protocol) | Official |
| 691 | TCP | MS Exchange Routing | Official | |
| 694 | TCP | UDP | Linux-HA High availability Heartbeat | Official |
| 695 | TCP | IEEE-MMS-SSL (IEEE Media Management System over SSL) | Official | |
| 698 | UDP | OLSR (Optimized Link State Routing) | Official | |
| 700 | TCP | EPP (Extensible Provisioning Protocol), a protocol for communication between domain name registries and registrars (RFC 5734) | Official | |
| 701 | TCP | LMP (Link Management Protocol (Internet)), a protocol that runs between a pair of nodes and is used to manage traffic engineering (TE) links | Official | |
| 702 | TCP | IRIS (Internet Registry Information Service) over BEEP (Blocks Extensible Exchange Protocol) (RFC 3983) | Official | |
| 706 | TCP | Secure Internet Live Conferencing (SILC) | Official | |
| 711 | TCP | Cisco Tag Distribution Protocol —being replaced by the MPLS Label Distribution Protocol | Official | |
| 712 | TCP | Topology Broadcast based on Reverse-Path Forwarding routing protocol (TBRPF) (RFC 3684) | Official | |
| 749 | TCP | UDP | Kerberos (protocol) administration | Official |
| 750 | UDP | kerberos-iv, Kerberos version IV | Official | |
| 751 | TCP | UDP | kerberos_master, Kerberos authentication | Unofficial |
| 752 | UDP | passwd_server, Kerberos Password (kpasswd) server | Unofficial | |
| 753 | TCP | Reverse Routing Header (rrh) | Official | |
| 753 | UDP | Reverse Routing Header (rrh) | Official | |
| 753 | UDP | userreg_server, Kerberos userreg server | Unofficial | |
| 754 | TCP | tell send | Official | |
| 754 | TCP | krb5_prop, Kerberos v5 slave propagation | Unofficial | |
| 754 | UDP | tell send | Official | |
| 760 | TCP | UDP | krbupdate [kreg], Kerberos registration | Unofficial |
| 782 | TCP | Conserver serial-console management server | Unofficial | |
| 783 | TCP | SpamAssassin spamd daemon | Unofficial | |
| 800 | UDP | mdbe daemon | Official | |
| 808 | TCP | Microsoft Net.TCP Port Sharing Service | Unofficial | |
| 829 | TCP | Certificate Management Protocol | Unofficial | |
| 843 | TCP | Adobe Flash | Unofficial | |
| 847 | TCP | DHCP Failover protocol | Official | |
| 848 | TCP | UDP | Group Domain Of Interpretation (GDOI) protocol | Official |
| 860 | TCP | iSCSI (RFC 3720) | Official | |
| 861 | TCP | UDP | OWAMP control (RFC 4656) | Official |
| 862 | TCP | UDP | TWAMP control (RFC 5357) | Official |
| 873 | TCP | rsync file synchronization protocol | Official | |
| 888 | TCP | cddbp, CD DataBase (CDDB) protocol (CDDBP), IBM Endpoint Manager Remote Control | Unofficial | |
| 897 | TCP | UDP | Brocade SMI-S RPC | Unofficial |
| 898 | TCP | UDP | Brocade SMI-S RPC SSL | Unofficial |
| 901 | TCP | Samba Web Administration Tool (SWAT) | Unofficial | |
| 901 | TCP | UDP | VMware Virtual Infrastructure Client (from managed device to management console) | Unofficial |
| 902 | TCP | UDP | ideafarm-door (IdeaFarm (tm) Operations) | Official |
| 902 | TCP | UDP | VMware Server Console (from management console to managed device) | Unofficial |
| 903 | TCP | UDP | ideafarm-panic (IdeaFarm (tm) Operations) | Official |
| 903 | TCP | VMware Remote Console | Unofficial | |
| 904 | TCP | VMware Server Alternate (if 902 is in use, i.e. SUSE linux) | Unofficial | |
| 911 | TCP | Network Console on Acid (NCA)—local tty redirection over OpenSSH | Unofficial | |
| 944 | UDP | Network File System Service | Unofficial | |
| 953 | TCP | UDP | Domain Name System (DNS) RNDC Service | Unofficial |
| 973 | UDP | Network File System over IPv6 Service | Unofficial | |
| 981 | TCP | SofaWare Technologies Remote HTTPS management for firewall devices running embedded Check Point FireWall-1 software | Unofficial | |
| 987 | TCP | Microsoft Windows SBS SharePoint | Unofficial | |
| 989 | TCP | UDP | FTPS Protocol (data): FTP over TLS/SSL | Official |
| 990 | TCP | UDP | FTPS Protocol (control): FTP over TLS/SSL | Official |
| 991 | TCP | UDP | NAS (Netnews Administration System) | Official |
| 992 | TCP | UDP | TELNET protocol over TLS/SSL | Official |
| 993 | TCP | Internet Message Access Protocol over TLS/SSL (IMAPS) | Official | |
| 994 | TCP | UDP | Internet Relay Chat over TLS/SSL (IRCS) | Official |
| 995 | TCP | Post Office Protocol 3 over TLS/SSL (POP3S) | Official | |
| 999 | TCP | ScimoreDB Database System | Unofficial | |
| 1002 | TCP | Opsware agent (aka cogbot) | Unofficial | |
| 1010 | TCP | ThinLinc Web Administration | Unofficial | |
| 1023 | TCP | UDP | Reserved | Official |
