Definition of Well-Known Port Numbers in Network Encyclopedia.
What is Well-known port numbers?
Well-known port numbers are port numbers for Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) that have been assigned to specific TCP/IP applications or services by the Internet Assigned Numbers Authority (IANA). Well-known port numbers are assigned within the range 0 through 1023 and are specified in Request for Comments (RFC) 1060. (The total range of possible port numbers is 0 through 65535.) The following table describes some of the well-known port numbers.
NOTE
“Registered ports” are port numbers that are not controlled by IANA but that IANA registers to indicate to the Internet community which vendor applications use them. Registered ports range from 1024 through 65535 and can be used by any process or program requesting it if the operating system has not already allocated it for a specific use. Programs and processes that communicate using remote procedure calls (RPCs) often randomly select a registered port for each RPC communication session.
Port Number List
Well-Known Port Numbers
| Port Number | Description |
| 0/tcp, udp | Reserved |
| 1/tcp, udp | TCP Port Service Multiplexer (tcpmux) |
| 2/tcp, udp | Management Utility (compressnet) |
| 3/tcp, udp | Compression Process (compressnet) |
| 4/tcp, udp | Unassigned |
| 5/tcp, udp | Remote Job Entry (rje) |
| 6/tcp, udp | Unassigned |
| 7/tcp, udp | Echo (echo) |
| 8/tcp, udp | Unassigned |
| 9/tcp, udp | Discard; alias = sink null (discard) |
| 10/tcp, udp | Unassigned |
| 11/tcp, udp | Active Users; alias = users (systat) |
| 12/tcp, udp | Unassigned |
| 13/tcp, udp | Daytime (daytime) |
| 14/tcp, udp | Unassigned |
| 15/tcp, udp | Unassigned (was netstat) |
| 16/tcp, udp | Unassigned |
| 17/tcp, udp | Quote of the Day; alias = quote (qotd) |
| 18/tcp, udp | Message Send Protocol (msp) |
| 19/tcp, udp | Character Generator; alias = ttytst source (chargen) |
| 20/tcp, udp | File Transfer (default data) (ftp-data) |
| 21/tcp, udp | File Transfer (control), connection dialog (ftp) |
| 22/tcp, udp | Unassigned |
| 23/tcp, udp | Telnet (telnet) |
| 24/tcp, udp | Any private mail system |
| 25/tcp, udp | Simple Mail Transfer; alias = mail (smtp) |
| 26/tcp, udp | Unassigned |
| 27/tcp, udp | NSW User System FE (nsw-fe) |
| 28/tcp, udp | Unassigned |
| 29/tcp, udp | MSG ICP (msg-icp) |
| 30/tcp, udp | Unassigned |
| 31/tcp, udp | MSG Authentication (msg-auth) |
| 32/tcp, udp | Unassigned |
| 33/tcp, udp | Display Support Protocol (dsp) |
| 34/tcp, udp | Unassigned |
| 35/tcp, udp | Any private printer server |
| 36/tcp, udp | Unassigned |
| 37/tcp, udp | Time; alias = timeserver (time) |
| 38/tcp, udp | Unassigned |
| 39/tcp, udp | Resource Location Protocol; alias = resource (rlp) |
| 40/tcp, udp | Unassigned |
| 41/tcp, udp | Graphics (graphics) |
| 42/tcp, udp | Host Name Server; alias = nameserver (nameserver) |
| 43/tcp, udp | Who Is; alias = nicname (nicname) |
| 44/tcp, udp | MPM FLAGS Protocol (mpm-flags) |
| 45/tcp, udp | Message Processing Module (mpm) |
| 46/tcp, udp | MPM (default send) (mpm-snd) |
| 47/tcp, udp | NI FTP (ni-ftp) |
| 48/tcp, udp | Unassigned |
| 49/tcp, udp | Login Host Protocol (login) |
| 50/tcp, udp | Remote Mail Checking Protocol (re-mail-ck) |
| 51/tcp, udp | IMP Logical Address Maintenance (la-maint) |
| 52/tcp, udp | XNS Time Protocol (xns-time) |
| 53/tcp, udp | Domain Name Server (domain) |
| 54/tcp, udp | XNS Clearinghouse (xns-ch) |
| 55/tcp, udp | ISI Graphics Language (isi-gl) |
| 56/tcp, udp | XNS Authentication (xns-auth) |
| 57/tcp, udp | Any private terminal access |
| 58/tcp, udp | XNS Mail (xns-mail) |
| 59/tcp, udp | Any private file service |
| 60/tcp, udp | Unassigned |
| 61/tcp, udp | NI MAIL (ni-mail) |
| 62/tcp, udp | ACA Services (acas) |
| 63/tcp, udp | VIA Systems – FTP (via-ftp) |
| 64/tcp, udp | Communications Integrator (CI) (covia) |
| 65/tcp, udp | TACACS-Database Service (tacacs-ds) |
| 66/tcp, udp | Oracle SQL*NET (sql*net) |
| 67/tcp, udp | DHCP/BOOTP Protocol Server (bootpc) |
| 68/tcp, udp | DHCP/BOOTP Protocol Server (bootpc) |
| 69/tcp, udp | Trivial File Transfer (tftp) |
| 70/tcp, udp | Gopher (gopher) |
| 71/tcp, udp | Remote Job Service (netrjs-1) |
| 72/tcp, udp | Remote Job Service (netrjs-2) |
| 73/tcp, udp | Remote Job Service (netrjs-3) |
| 74/tcp, udp | Remote Job Service (netrjs-4) |
| 75/udp | Any private dial-out service |
| 76/tcp, udp | Unassigned |
| 77/tcp, udp | Any private RJE service |
| 78/tcp, udp | Vettcp (vettcp) |
| 79/tcp, udp | Finger (finger) |
| 80/tcp, udp | World Wide Web HTTP (www) |
| 81/tcp, udp | HOSTS2 Name Server (hosts2-ns) |
| 82/tcp, udp | XFER Utility (xfer) |
| 83/tcp, udp | MIT ML Device (mit-ml-dev) |
| 84/tcp, udp | Common Trace Facility (ctf) |
| 85/tcp, udp | MIT ML Device (mit-ml-dev) |
| 86/tcp, udp | Micro Focus Cobol (mfcobol) |
| 87/tcp, udp | Any private terminal link; alias = ttylink |
| 88/tcp, udp | Kerberos (kerberos) |
| 89/tcp, udp | SU/MIT Telnet Gateway (su-mit-tg) |
| 90/tcp, udp | DNSIX Security Attribute Token Map |
| 91/tcp, udp | MIT Dover Spooler (mit-dov) |
| 92/tcp, udp | Network Printing Protocol (npp) |
| 93/tcp, udp | Device Control Protocol (dcp) |
| 94/tcp, udp | Tivoli Object Dispatcher (objcall) |
| 95/tcp, udp | SUPDUP (supdup) |
| 96/tcp, udp | DIXIE Protocol Specification (dixie) |
| 97/tcp, udp | Swift Remote Virtual File Protocol (swift-rvf) |
| 98/tcp, udp | TAC News (tacnews) |
| 99/tcp, udp | Metagram Relay (metagram) |
| 100/tcp | (unauthorized use) (newacct) |
| 101/tcp, udp | NIC Host Name Server; alias = hostname (hostname) |
| 102/tcp, udp | ISO-TSAP (iso-tsap) |
| 103/tcp, udp | Genesis Point-to-Point Trans Net; alias = webster (gppitnp) |
| 104/tcp, udp | ACR-NEMA Digital Imag. & Comm. 300 (acr-nema) |
| 105/tcp, udp | Mailbox Name Nameserver (csnet-ns) |
| 106/tcp, udp | 3COM-TSMUX (3com-tsmux) |
| 107/tcp, udp | Remote Telnet Service (rtelnet) |
| 108/tcp, udp | SNA Gateway Access Server (snagas) |
| 109/tcp, udp | Post Office Protocol version 2 (POP2); alias = postoffice (pop2) |
| 110/tcp, udp | Post Office Protocol version 3 (POP3); alias = postoffice (pop3) |
| 111/tcp, udp | SUN Remote Procedure Call (sunrpc) |
| 112/tcp, udp | McIDAS Data Transmission Protocol (mcidas) |
| 113/tcp, udp | Authentication Service; alias = authentication (auth) |
| 114/tcp, udp | Audio News Multicast (audionews) (audionews) |
| 115/tcp, udp | Simple File Transfer Protocol (sftp) (sftp) |
| 116/tcp, udp | ANSA REX Notify (ansanotify) |
| 117/tcp, udp | UUCP Path Service (uucp-path) |
| 118/tcp, udp | SQL Services (sqlserv) |
| 119/tcp, udp | Network News Transfer Protocol (NNTP); usenet (nntp) |
| 120/tcp, udp | CFDPTKT (cfdptkt) |
| 121/tcp, udp | Encore Expedited Remote Pro. Call (erpc) (erpc) |
| 122/tcp, udp | SMAKYNET (smakynet) |
| 123/tcp, udp | Network Time Protocol; alias = ntpd ntp (ntp) |
| 124/tcp, udp | ANSA REX Trader (ansatrader) |
| 125/tcp, udp | Locus PC-Interface Net Map Server (locus-map) |
| 126/tcp, udp | Unisys Unitary Login (unitary) |
| 127/tcp, udp | Locus PC-Interface Conn Server (locus-con) |
| 128/tcp, udp | GSS X License Verification (gss-xlicen) |
| 129/tcp, udp | Password Generator Protocol (pwdgen) |
| 130/tcp, udp | Cisco FNATIVE (cisco-fna) (cisco-fna) |
| 131/tcp, udp | Cisco TNATIVE (cisco-tna) (cisco-tna) |
| 132/tcp, udp | Cisco SYSMAINT (cisco-sys) (cisco-sys) |
| 133/tcp, udp | Statistics Service (statsrv) |
| 134/tcp, udp | INGRES-NET Service (ingres-net) |
| 135/tcp, udp | Location Service (loc-srv) |
| 136/tcp, udp | PROFILE Naming System (profile) |
| 137/tcp, udp | NetBIOS Name Service (netbios-ns) |
| 138/tcp, udp | NetBIOS Datagram Service (netbios-dgm) |
| 139/tcp, udp | NetBIOS Session Service (netbios-ssn) |
| 140/tcp, udp | EMFIS Data Service (emfis-data) |
| 141/tcp, udp | EMFIS Control Service (emfis-cntl) |
| 142/tcp, udp | Britton-Lee IDM (bl-idm) |
| 143/tcp, udp | Interim Mail Access Protocol v2 (imap2) |
| 144/tcp, udp | NewS; alias = news (news) |
| 145/tcp, udp | UAAC Protocol (uaac) |
| 146/tcp, udp | ISO-IP0 (iso-ip0) |
| 147/tcp, udp | ISO-IP (iso-ip) |
| 148/tcp, udp | CRONUS-SUPPORT (cronus) |
| 149/tcp, udp | AED 512 Emulation Service (aed-512) |
| 150/tcp, udp | SQL-NET (sql-net) |
| 151/tcp, udp | HEMS (hems) |
| 152/tcp, udp | Background File Transfer Program (bftp) |
| 153/tcp, udp | SGMP; alias = sgmp (sgmp) |
| 154/tcp, udp | Netscape (netsc-prod) |
| 155/tcp, udp | Netscape (netsc-dev) |
| 156/tcp, udp | SQL Service (sqlsrv) |
| 157/tcp, udp | KNET/VM Command/Message Protocol (knet-cmp) |
| 158/tcp, udp | PCMail Server; alias = repository (pcmail-srv) |
| 159/tcp, udp | NSS-Routing (nss-routing) |
| 160/tcp, udp | SGMP-TRAPS (sgmp-traps) |
| 161/tcp, udp | SNMP; alias = snmp (snmp) |
| 162/tcp, udp | SNMPTRAP (snmptrap) |
| 163/tcp, udp | CMIP/TCP Manager (cmip-man) |
| 164/tcp, udp | CMIP/TCP Agent (cmip-agent) |
| 165/tcp, udp | Xerox (xns-courier) |
| 166/tcp, udp | Sirius Systems (s-net) |
| 167/tcp, udp | NAMP (namp) |
| 168/tcp, udp | RSVD (rsvd) |
| 169/tcp, udp | SEND (send) |
| 170/tcp, udp | Network PostScript (print-srv) |
| 171/tcp, udp | Network Innovations Multiplex (multiplex) |
| 172/tcp, udp | Network Innovations CL/1 (cl/1) |
| 173/tcp, udp | Xyplex (xyplex-mux) |
| 174/tcp, udp | MAILQ (mailq) |
| 175/tcp, udp | VMNET (vmnet) |
| 176/tcp, udp | GENRAD-MUX (genrad-mux) |
| 177/tcp, udp | X Display Manager Control Protocol (xdmcp) |
| 178/tcp, udp | NextStep Window Server (nextstep) |
| 179/tcp, udp | Border Gateway Protocol (BGP) (bgp) |
| 180/tcp, udp | Intergraph (ris) |
| 181/tcp, udp | Unify (unify) |
| 182/tcp, udp | Unisys Audit SITP (audit) |
| 183/tcp, udp | OCBinder (ocbinder) |
| 184/tcp, udp | OCServer (ocserver) |
| 185/tcp, udp | Remote-KIS (remote-kis) |
| 186/tcp, udp | KIS Protocol (kis) |
| 187/tcp, udp | Application Communication Interface (aci) |
| 188/tcp, udp | Plus Five’s MUMPS (mumps) |
| 189/tcp, udp | Queued File Transport (qft) |
| 190/tcp, udp | Gateway Access Control Protocol (gacp) |
| 191/tcp, udp | Prospero (prospero) |
| 192/tcp, udp | OSU Network Monitoring System (osu-nms) |
| 193/tcp, udp | Spider Remote Monitoring Protocol (srmp) |
| 194/tcp, udp | Internet Relay Chat (IRC) Protocol (irc) |
| 195/tcp, udp | DNSIX Network Level Module Audit (dn6-nlm-aud) |
| 196/tcp, udp | DNSIX Session Mgt Module Audit Redir (dn6-smm-red) |
| 197/tcp, udp | Directory Location Service (dls) |
| 198/tcp, udp | Directory Location Service Monitor (dls-mon) |
| 199/tcp, udp | SMUX (smux) |
| 200/tcp, udp | IBM System Resource Controller (src) |
| 201/tcp, udp | AppleTalk Routing Maintenance (at-rtmp) |
| 202/tcp, udp | AppleTalk Name Binding (at-nbp) |
| 203/tcp, udp | AppleTalk Unused (at-3) |
| 204/tcp, udp | AppleTalk Echo (at-echo) |
| 205/tcp, udp | AppleTalk Unused (at-5) |
| 206/tcp, udp | AppleTalk Zone Information (at-zis) |
| 207/tcp, udp | AppleTalk Unused (at-7) |
| 208/tcp, udp | AppleTalk Unused (at-8) |
| 209/tcp, udp | Trivial Authenticated Mail Protocol (tam) |
| 210/tcp, udp | ANSI Z39.50 (z39.50) |
| 211/tcp, udp | Texas Instruments 914C/G Terminal (914c/g) |
| 212/tcp, udp | ATEXSSTR (anet) |
| 213/tcp, udp | Internetwork Packet Exchange (IPX) (ipx) |
| 214/tcp, udp | VM PWSCS (vmpwscs) |
| 215/tcp, udp | Insignia Solutions (softpc) |
| 216/tcp, udp | Access Technology License Server (atls) |
| 217/tcp, udp | dBASE UNIX (dbase) |
| 218/tcp, udp | Netix Message Posting Protocol (mpp) |
| 219/tcp, udp | Unisys ARPs (uarps) |
| 220/tcp, udp | Interactive Mail Access Protocol v3 (imap3) |
| 221/tcp, udp | Berkeley rlogind with SPX auth (fln-spx) |
| 222/tcp, udp | Berkeley rshd with SPX auth (fsh-spx) |
| 223/tcp, udp | Certificate Distribution Center (cdc) |
| 224–241 | Reserved |
| 243/tcp, udp | Survey Measurement (sur-meas) |
| 245/tcp, udp | LINK (link) |
| 246/tcp, udp | Display Systems Protocol (dsp3270) |
| 247–255 | Reserved |
| 345/tcp, udp | Perf Analysis Workbench (pawserv) |
| 346/tcp, udp | Zebra server (zserv) |
| 347/tcp, udp | Fatmen Server (fatserv) |
| 371/tcp, udp | Clearcase (clearcase) |
| 372/tcp, udp | UNIX Listserv (ulistserv) |
| 373/tcp, udp | Legent Corporation (legent-1) |
| 374/tcp, udp | Legent Corporation (legent-2) |
| 512/tcp | |
| 512/udp | biff |
| 513/tcp | Remote logon such as Telnet; (login) |
| 513/udp | who |
| 514/tcp | Like exec, but automatic authentication is performed as for logon server (cmd) |
| 514/udp | (syslog) |
| 515/tcp, udp | Spooler; spooler |
| 517/tcp, udp | talk |
| 518/tcp, udp | (ntalk) |
| 519/tcp, udp | Unixtime (utime) |
| 520/tcp | Extended filename server (efs) |
| 520/udp | Local routing process (on site); router routed |
| 525/tcp, udp | Timeserver (timed) |
| 526/tcp, udp | Newdate (tempo) |
| 530/tcp, udp | RPC (courier) |
| 531/tcp | Chat (conference) |
| 531/udp | MIT disk (rvd-control) |
| 532/tcp, udp | Readnews (netnews) |
| 533/tcp, udp | For emergency broadcasts (netwall) |
| 540/tcp, udp | Uucpd (uucp) |
| 543/tcp, udp | (klogin) |
| 544/tcp, udp | Krcmd; alias = cmd (kshell) |
| 550/tcp, udp | New-who (new-rwho) |
| 555/tcp, udp | (dsf) |
| 556/tcp, udp | Rfs server; alias = rfs_server rfs (remotefs) |
| 560/tcp, udp | Rmonitord (rmonitor) |
| 561/tcp, udp | (monitor) |
| 562/tcp, udp | Chcmd (chshell) |
| 564/tcp, udp | Plan 9 file service (9pfs) |
| 565/tcp, udp | Whoami (whoami) |
| 570/tcp, udp | Demon (meter) |
| 571/tcp, udp | Udemon (meter) |
| 600/tcp, udp | Sun IPC server (ipcserver) |
| 607/tcp, udp | Nqs (nqs) |
| 666/tcp, udp | Reserved for Id software (doom) |
| 704/tcp, udp | Errlog copy/server daemon (elcsd) |
| 721–731/tcp | printer |
| 740/tcp, udp | NETscout Control Protocol (netcp) |
| 741/tcp, udp | NetGW (netgw) |
| 742/tcp, udp | Network-based Rev. Cont. Sys. (netrcs) |
| 744/tcp, udp | Flexible License Manager (flexlm) |
| 747/tcp, udp | Fujitsu Device Control (fujitsu-dev) |
| 748/tcp, udp | Russell Info Sci Calendar Manager (ris-cm) |
| 749/tcp, udp | Kerberos administration (kerberos-adm) |
| 750/tcp | Kerberos authentication; alias = kdc (rfile) |
| 750/udp | (loadav) |
| 751/tcp, udp | Kerberos authentication (pump) |
| 752/tcp, udp | Kerberos password server (qrh) |
| 753/tcp, udp | Kerberos userreg server (rrh) |
| 754/tcp, udp | Send; Kerberos slave propagation (tell) |
| 758/tcp, udp | (nlogin) |
| 759/tcp, udp | (con) |
| 760/tcp, udp | (ns) |
| 761/tcp, udp | (rxe) |
| 762/tcp, udp | (quotad) |
| 763/tcp, udp | (cycleserv) |
| 764/tcp, udp | (omserv) |
| 765/tcp, udp | (webster) |
| 767/tcp, udp | Phone (phonebook) |
| 769/tcp, udp | (vid) |
| 770/tcp, udp | (cadlock) |
| 771/tcp, udp | (rtip) |
| 772/tcp, udp | (cycleserv2) |
| 773/tcp | (submit) |
| 773/udp | (notify) |
| 774/tcp | (rpasswd) |
| 774/udp | (acmaint_dbd) |
| 775/tcp | (entomb) |
| 775/udp | (acmaint_transd) |
| 776/tcp, udp | (wpages) |
| 780/tcp, udp | (wpgs) |
| 781/tcp, udp | HP performance data collector (hp-collector) |
| 782/tcp, udp | HP performance data managed node (hp-managed-node) |
| 783/tcp, udp | HP performance data alarm manager (hp-alarm-mgr) |
| 800/tcp, udp | (mdbs_daemon) |
| 801/tcp, udp | (device) |
| 888/tcp | Logon and environment passing (erlogin) |
| 996/tcp, udp | XTREE License Server (xtreelic) |
| 997/tcp, udp | (maitrd) |
| 998/tcp | (busboy) |
| 998/udp | (puparp) |
| 999/tcp | (garcon) |
| 999/udp | Applix ac (applix) |
| 999/tcp, udp | (puprouter) |
| 1000/tcp | (cadlock) |
| 1000/udp | (ock) |