Port Assignments for Well Known Ports

Well known services are defined by RFC 1060. The relationship between the well known services and the well known ports is described in this excerpt from RFC 1340 (J. Reynolds and J. Postal, July 1992):

The well known ports are controlled and assigned by the Internet Assigned Numbers Authority (IANA), and on most systems can only be used by system (or root) processes or by programs executed by privileged users.

Ports are used in TCP to name the ends of logical connections that carry long term conversations. For the purpose of providing services to unknown callers, a service contact port is defined. This list specifies the port used by the server process as its contact port. The contact port is sometimes called the "well known port."

UDP ports are not the same as TCP ports, though to the extent possible, TCP and UDP may use the same port assignments. The UDP specification is defined in RFC 768.

The assigned ports use a small portion of the possible port numbers. For many years, the assigned ports were in the range 0 – 255. Recently, the range for assigned ports managed by the IANA has been expanded to the range
0 – 1023.

The following table describes both TCP and UDP port assignments for well known ports.

Table B.1 Port Assignments for Well Known Ports

Decimal

Keyword

Description

0/tcp, udp

Reserved

1/tcp, udp

tcpmux

TCP Port Service Multiplexer

2/tcp, udp

compressnet

Management Utility

3/tcp, udp

compressnet

Compression Process

4/tcp, udp

Unassigned

5/tcp, udp

rje

Remote Job Entry

6/tcp, udp

Unassigned

7/tcp, udp

echo

Echo

8/tcp, udp

Unassigned

9/tcp, udp

discard

Discard; alias=sink null

10/tcp, udp

Unassigned

11/udp

systat

Active Users; alias=users

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

qotd

Quote of the Day; alias=quote

18/tcp, udp

msp

Message Send Protocol

19/tcp, udp

chargen

Character Generator; alias=ttytst source

20/tcp, udp

ftp-data

File Transfer [Default Data]

21/tcp, udp

ftp

File Transfer [Control], connection dialog

22/tcp, udp

Unassigned

23/tcp, udp

telnet

Telnet

24/tcp, udp

Any private mail system

25/tcp, udp

smtp

Simple Mail Transfer; alias=mail

26/tcp, udp

Unassigned

27/tcp, udp

nsw-fe

NSW User System FE

28/tcp, udp

Unassigned

29/tcp, udp

msg-icp

MSG ICP

30/tcp, udp

Unassigned

31/tcp, udp

msg-auth

MSG Authentication

32/tcp, udp

Unassigned

33/tcp, udp

dsp

Display Support Protocol

34/tcp, udp

Unassigned

35/tcp, udp

Any private printer server

36/tcp, udp

Unassigned

37/tcp, udp

time

Time; alias=timeserver

38/tcp, udp

Unassigned

39/tcp, udp

rlp

Resource Location Protocol; alias=resource

40/tcp, udp

Unassigned

41/tcp, udp

graphics

Graphics

42/tcp, udp

nameserver

Host Name Server; alias=nameserver

43/tcp, udp

nicname

Who Is; alias=nicname

44/tcp, udp

mpm-flags

MPM FLAGS Protocol

45/tcp, udp

mpm

Message Processing Module

46/tcp, udp

mpm-snd

MPM [default send]

47/tcp, udp

ni-ftp

NI FTP

48/tcp, udp

Unassigned

49/tcp, udp

login

Login Host Protocol

50/tcp, udp

re-mail-ck

Remote Mail Checking Protocol

51/tcp, udp

la-maint

IMP Logical Address Maintenance

52/tcp, udp

xns-time

XNS Time Protocol

53/tcp, udp

domain

Domain Name Server

54/tcp, udp

xns-ch

XNS Clearinghouse

55/tcp, udp

isi-gl

ISI Graphics Language

56/tcp, udp

xns-auth

XNS Authentication

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

acas

ACA Services

63/tcp, udp

via-ftp

VIA Systems - FTP

64/tcp, udp

covia

Communications Integrator (CI)

65/tcp, udp

tacacs-ds

TACACS-Database Service

66/tcp, udp

sql*net

Oracle SQL*NET

67/tcp, udp

bootpc

DHCP/BOOTP Protocol Server

68/tcp, udp

bootpc

DHCP/BOOTP Protocol Server

69/ udp

tftp

Trivial File Transfer

70/tcp, udp

gopher

Gopher

71/tcp, udp

netrjs-1

Remote Job Service

72/tcp, udp

netrjs-2

Remote Job Service

73/tcp, udp

netrjs-3

Remote Job Service

74/tcp, udp

netrjs-4

Remote Job Service

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

www

World Wide Web HTTP

81/tcp, udp

hosts2-ns

HOSTS2 Name Server

82/tcp, udp

xfer

XFER Utility

83/tcp, udp

mit-ml-dev

MIT ML Device

84/tcp, udp

ctf

Common Trace Facility

85/tcp, udp

mit-ml-dev

MIT ML Device

86/tcp, udp

mfcobol

Micro Focus Cobol

87/tcp, udp

Any private terminal link; alias=ttylink

88/tcp, udp

kerberos

Kerberos

89/tcp

su-mit-tg

SU/MIT Telnet Gateway

89/udp

su-mit-tg

SU/MIT Telnet Gateway

90/tcp, udp

DNSIX Security Attribute Token Map

91/tcp, udp

mit-dov

MIT Dover Spooler

92/tcp, udp

npp

Network Printing Protocol

93/tcp, udp

dcp

Device Control Protocol

94/tcp, udp

objcall

Tivoli Object Dispatcher

95/tcp, udp

supdup

SUPDUP

96/tcp, udp

dixie

DIXIE Protocol Specification

97/tcp, udp

swift-rvf

Swift Remote Virtual File Protocol

98/tcp, udp

tacnews

TAC News

99/tcp, udp

metagram

Metagram Relay

100/tcp

newacct

[unauthorized use]

101/tcp, udp

hostname

NIC Host Name Server; alias=hostname

102/tcp, udp

iso-tsap

ISO-TSAP

103/tcp, udp

gppitnp

Genesis Point-to-Point Trans Net; alias=webster

104/tcp, udp

acr-nema

ACR-NEMA Digital Imag. & Comm. 300

105/tcp, udp

csnet-ns

Mailbox Name Nameserver

106/tcp, udp

3com-tsmux

3COM-TSMUX

107/tcp, udp

rtelnet

Remote Telnet Service

108/tcp, udp

snagas

SNA Gateway Access Server

109/tcp, udp

pop2

Post Office Protocol - Version 2; alias=postoffice

110/tcp, udp

pop3

Post Office Protocol - Version 3; alias=postoffice

111/tcp, udp

sunrpc

SUN Remote Procedure Call

112/tcp, udp

mcidas

McIDAS Data Transmission Protocol

113/tcp, udp

auth

Authentication Service; alias=authentication

114/tcp, udp

audionews

Audio News Multicast

115/tcp, udp

sftp

Simple File Transfer Protocol

116/tcp, udp

ansanotify

ANSA REX Notify

117/tcp, udp

uucp-path

UUCP Path Service

118/tcp, udp

sqlserv

SQL Services

119/tcp, udp

nntp

Network News Transfer Protocol; alias=usenet

120/tcp, udp

cfdptkt

CFDPTKT

121/tcp, udp

erpc

Encore Expedited Remote Pro.Call

122/tcp, udp

smakynet

SMAKYNET

123/tcp, udp

ntp

Network Time Protocol; alias=ntpd ntp

124/tcp, udp

ansatrader

ANSA REX Trader

125/tcp, udp

locus-map

Locus PC-Interface Net Map Server

126/tcp, udp

unitary

Unisys Unitary Login

127/tcp, udp

locus-con

Locus PC-Interface Conn Server

128/tcp, udp

gss-xlicen

GSS X License Verification

129/tcp, udp

pwdgen

Password Generator Protocol

130/tcp, udp

cisco-fna

Cisco FNATIVE

131/tcp, udp

cisco-tna

Cisco TNATIVE

132/tcp, udp

cisco-sys

Cisco SYSMAINT

133/tcp, udp

statsrv

Statistics Service

134/tcp, udp

ingres-net

INGRES-NET Service

135/tcp, udp

loc-srv

Location Service

136/tcp, udp

profile

PROFILE Naming System

137/tcp, udp

netbios-ns

NetBIOS Name Service

138/tcp, udp

netbios-dgm

NetBIOS Datagram Service

139/tcp, udp

netbios-ssn

NetBIOS Session Service

140/tcp, udp

emfis-data

EMFIS Data Service

141/tcp, udp

emfis-cntl

EMFIS Control Service

142/tcp, udp

bl-idm

Britton-Lee IDM

143/tcp, udp

imap2

Interim Mail Access Protocol v2

144/tcp, udp

news

NewS; alias=news

145/tcp, udp

uaac

UAAC Protocol

146/tcp, udp

iso-ip0

ISO-IP0

147/tcp, udp

iso-ip

ISO-IP

148/tcp, udp

cronus

CRONUS-SUPPORT

149/tcp, udp

aed-512

AED 512 Emulation Service

150/tcp, udp

sql-net

SQL-NET

151/tcp, udp

hems

HEMS

152/tcp, udp

bftp

Background File Transfer Program

153/tcp, udp

sgmp

SGMP; alias=sgmp

154/tcp, udp

netsc-prod

Netscape

155/tcp, udp

netsc-dev

Netscape

156/tcp, udp

sqlsrv

SQL Service

157/tcp, udp

knet-cmp

KNET/VM Command/Message Protocol

158/tcp, udp

pcmail-srv

PCMail Server; alias=repository

159/tcp, udp

nss-routing

NSS-Routing

160/tcp, udp

sgmp-traps

SGMP-TRAPS

161/tcp, udp

snmp

SNMP; alias=snmp

162/tcp, udp

snmptrap

SNMPTRAP

163/tcp, udp

cmip-man

CMIP/TCP Manager

164/tcp, udp

cmip-agent

CMIP/TCP Agent

165/tcp, udp

xns-courier

Xerox

166/tcp, udp

s-net

Sirius Systems

167/tcp, udp

namp

NAMP

168/tcp, udp

rsvd

RSVD

169/tcp, udp

send

SEND

170/tcp, udp

print-srv

Network PostScript

171/tcp, udp

multiplex

Network Innovations Multiplex

172/tcp, udp

cl/1

Network Innovations CL/1

173/tcp, udp

xyplex-mux

Xyplex

174/tcp, udp

mailq

MAILQ

175/tcp, udp

vmnet

VMNET

176/tcp, udp

genrad-mux

GENRAD-MUX

177/tcp, udp

xdmcp

X Display Manager Control Protocol

178/tcp, udp

nextstep

NextStep Window Server

179/tcp, udp

bgp

Border Gateway Protocol

180/tcp, udp

ris

Intergraph

181/tcp, udp

unify

Unify

182/tcp, udp

audit

Unisys Audit SITP

183/tcp, udp

ocbinder

OCBinder

184/tcp, udp

ocserver

OCServer

185/tcp, udp

remote-kis

Remote-KIS

186/tcp, udp

kis

KIS Protocol

187/tcp, udp

aci

Application Communication Interface

188/tcp, udp

mumps

Plus Five's MUMPS

189/tcp, udp

qft

Queued File Transport

190/tcp, udp

gacp

Gateway Access Control Protocol

191/tcp, udp

prospero

Prospero

192/tcp, udp

osu-nms

OSU Network Monitoring System

193/tcp, udp

srmp

Spider Remote Monitoring Protocol

194/tcp, udp

irc

Internet Relay Chat Protocol

195/tcp, udp

dn6-nlm-aud

DNSIX Network Level Module Audit

196/tcp, udp

dn6-smm-red

DNSIX Session Mgt Module Audit Redir

197/tcp, udp

dls

Directory Location Service

198/tcp, udp

dls-mon

Directory Location Service Monitor

199/tcp, udp

smux

SMUX

200/tcp, udp

src

IBM System Resource Controller

201/tcp, udp

at-rtmp

AppleTalk Routing Maintenance

202/tcp, udp

at-nbp

AppleTalk Name Binding

203/tcp, udp

at-3

AppleTalk Unused

204/tcp, udp

at-echo

AppleTalk Echo

205/tcp, udp

at-5

AppleTalk Unused

206/tcp, udp

at-zis

AppleTalk Zone Information

207/tcp, udp

at-7

AppleTalk Unused

208/tcp, udp

at-8

AppleTalk Unused

209/tcp, udp

tam

Trivial Authenticated Mail Protocol

210/tcp, udp

z39.50

ANSI Z39.50

211/tcp, udp

914c/g

Texas Instruments 914C/G Terminal

212/tcp, udp

anet

ATEXSSTR

213/tcp, udp

ipx

IPX

214/tcp, udp

vmpwscs

VM PWSCS

215/tcp, udp

softpc

Insignia Solutions

216/tcp, udp

atls

Access Technology License Server

217/tcp, udp

dbase

dBASE UNIX

218/tcp, udp

mpp

Netix Message Posting Protocol

219/tcp, udp

uarps

Unisys ARPs

220/tcp, udp

imap3

Interactive Mail Access Protocol v3

221/tcp, udp

fln-spx

Berkeley rlogind with SPX auth

222/tcp, udp

fsh-spx

Berkeley rshd with SPX auth

223/tcp, udp

cdc

Certificate Distribution Center

224-241

Reserved

243/tcp, udp

sur-meas

Survey Measurement

245/tcp, udp

link

LINK

246/tcp, udp

dsp3270

Display Systems Protocol

247-255

Reserved

345/tcp, udp

pawserv

Perf Analysis Workbench

346/tcp, udp

zserv

Zebra server

347/tcp, udp

fatserv

Fatmen Server

371/tcp, udp

clearcase

Clearcase

372/tcp, udp

ulistserv

UNIX Listserv

373/tcp, udp

legent-1

Legent Corporation

374/tcp, udp

legent-2

Legent Corporation

512/tcp

print

Windows NT Server and Windows NT Workstation version 4.0 can send LPD client print jobs from any available reserved port between 512 and 1023. See also description for ports 721 to 731.

512/udp

biff

Used by mail system to notify users of new mail received; currently receives messages only from processes on the same computer; alias=comsat

513/tcp

login

Remote logon like telnet; automatic authentication performed, based on privileged port numbers and distributed databases that identify "authentication domains"

513/udp

who

Maintains databases showing who's logged on to the computers on a local net and the load average of the computer; alias=whod

514/tcp

cmd

Like exec, but automatic authentication is performed as for logon server

514/udp

syslog

515/tcp, udp

printer

Spooler; alias=spooler. The print server LPD service will listen on tcp port 515 for incoming connections.

517/tcp, udp

talk

Like tenex link, but across computers; unfortunately, doesn't use link protocol (this is actually just a rendezvous port from which a TCP connection is established)

518/tcp, udp

ntalk

519/tcp, udp

utime

Unixtime

520/tcp

efs

Extended file name server

520/udp

router

Local routing process (on site); uses variant of Xerox NS routing information protocol;alias=router routed

525/tcp, udp

timed

Timeserver

526/tcp, udp

tempo

Newdate

530/tcp, udp

courier

RPC

531/tcp

conference

Chat

531/udp

rvd-control

MIT disk

532/tcp, udp

netnews

Readnews

533/tcp, udp

netwall

For emergency broadcasts

540/tcp, udp

uucp

Uucpd

543/tcp, udp

klogin

544/tcp, udp

kshell

Krcmd; alias=cmd

550/tcp, udp

new-rwho

New-who

555/tcp, udp

dsf

556/tcp, udp

remotefs

Rfs server; alias=rfs_server rfs

560/tcp, udp

rmonitor

Rmonitord

561/tcp, udp

monitor

562/tcp, udp

chshell

Chcmd

564/tcp, udp

9pfs

Plan 9 file service

565/tcp, udp

whoami

Whoami

570/tcp, udp

meter

Demon

571/tcp, udp

meter

Udemon

600/tcp, udp

ipcserver

Sun IPC server

607/tcp, udp

nqs

Nqs

666/tcp, udp

mdqs

704/tcp, udp

elcsd

Errlog copy/server daemon

721-731/tcp

printer

Under Windows NT 3.5x, all TCP/IP print jobs sent from a Windows NT computer were sourced from TCP ports 721 through 731. This is changed for Windows NT Server and Windows NT Workstation version 4.0, which sources LPD client print jobs from any available reserved port between 512 and 1023.

740/tcp, udp

netcp

NETscout Control Protocol

741/tcp, udp

netgw

NetGW

742/tcp, udp

netrcs

Network based Rev. Cont. Sys.

744/tcp, udp

flexlm

Flexible License Manager

747/tcp, udp

fujitsu-dev

Fujitsu Device Control

748/tcp, udp

ris-cm

Russell Info Sci Calendar Manager

749/tcp, udp

kerberos-adm

Kerberos administration

750/tcp

rfile

Kerberos authentication; alias=kdc

750/udp

loadav

751/tcp, udp

pump

Kerberos authentication

752/tcp, udp

qrh

Kerberos password server

753/tcp, udp

rrh

Kerberos userreg server

754/tcp, udp

tell

Send; Kerberos slave propagation

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

phonebook

Phone

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-collector

HP performance data collector

782/tcp, udp

hp-managed-node

HP performance data managed node

783/tcp, udp

hp-alarm-mgr

HP performance data alarm manager

800/tcp, udp

mdbs_daemon

801/tcp, udp

device

888/tcp

erlogin

Logon and environment passing

996/tcp, udp

xtreelic

XTREE License Server

997/tcp, udp

maitrd

998/tcp

busboy

998/udp

puparp

999/tcp

garcon

999/udp

applix

Applix ac

999/tcp, udp

puprouter

1000/tcp

cadlock

1000/udp

ock