Both TCP and UDP use well-known ports, also known as service contact ports. The port names reflect the specific TCP and UDP applications. Ports are the end points of a connection, providing a convenient method for accessing and addressing the connection end.
The following list does not include all TCP and UDP ports, but it does include all those you are likely to encounter. The rest are assigned for historical or experimental reasons.
|
Port |
Name |
Description |
|
1
|
TCPMUX
|
TCP Port Service Multiplexer
|
|
5
|
RJE
|
Remote Job Entry
|
|
7
|
ECHO
|
Echo
|
|
9
|
DISCARD
|
Discard
|
|
11
|
USERS
|
Active Users
|
|
13
|
DAYTIME
|
Daytime
|
|
17
|
Quote
|
Quote of the Day
|
|
19
|
CHARGEN
|
Character Generator
|
|
20
|
FTP-DATA
|
File Transfer (Data Channel)
|
|
21
|
FTP
|
File Transfer (Control Channel)
|
|
23
|
TELNET
|
TELNET
|
|
25
|
SMTP
|
Simple Mail Transfer
|
|
27
|
NSW-FE
|
NSW User System FE
|
|
29
|
MSG-ICP
|
MSG-ICP
|
|
31
|
MSG-AUTH
|
MSG Authentication
|
|
33
|
DSP
|
Display Support Protocol
|
|
35
|
Private Printer Server
| |
|
37
|
TIME
|
Time
|
|
39
|
RLP
|
Resource Location Protocol
|
|
41
|
GRAPHICS
|
Graphics
|
|
42
|
NAMESERVER
|
Host Name Server
|
|
43
|
NICNAME
|
Who Is
|
|
49
|
LOGIN
|
Login Host Protocol
|
|
53
|
DOMAIN
|
Domain Name Server
|
|
67
|
BOOTPS
|
Bootstrap Protocol Server
|
|
68
|
BOOTPC
|
Bootstrap Protocol Client
|
|
69
|
TFTP
|
Trivial File Transfer Protocol
|
|
79
|
FINGER
|
Finger
|
|
101
|
HOSTNAMENIC
|
Host Name Server
|
|
102
|
ISO-TSAP
|
ISO TSAP
|
|
103
|
X400
|
X.400
|
|
104
|
X400SND
|
X.400 SND
|
|
105
|
CSNET-NSCSNET
|
Mailbox Name Server
|
|
109
|
POP2
|
Post Office Protocol v2
|
|
110
|
POP3
|
Post Office Protocol v3
|
|
111
|
SUNRPC
|
SUN RPC Portmap
|
|
137
|
NETBIOS-NS
|
NETBIOS Name Service
|
|
138
|
NETBIOS-DGMNET
|
BIOS Datagram Service
|
|
139
|
NETBIOS-SSNNET
|
BIOS Session Service
|
|
146
|
ISO-TP0
|
ISO TP0
|
|
147
|
ISO-IP
|
ISO IP
|
|
150
|
SQL-NET
|
SQL-NET
|
|
153
|
SGMP
|
SGMP
|
|
156
|
SQLSRV
|
SQL Service
|
|
160
|
SGMP-TRAP5
|
SGMP TRAPS
|
|
161
|
SNMP
|
SNMP
|
|
162
|
SNMPTRAP
|
SNMPTRAP
|
|
163
|
CMIP-MANAGE
|
CMIP/TCP Manager
|
|
164
|
CMIP-AGENT
|
CMIP/TCP Agent
|
|
165
|
XNS-COURIER
|
Xerox Network
|
|
179
|
BGP
|
Border Gateway Protocol |
