B
B
Appendix B
Well Known Port Numbers
In this appendix, which is included for your reference, we provide a list of Well Known port
numbers that may cause network problems if you set NPort IA5150/5250 to one of these ports.
Refer to RFC 1700 for Well Known port numbers, or refer to the following introduction from the
IANA.
The port numbers are divided into three ranges: the Well Known Ports, the Registered Ports, and
the Dynamic and/or Private Ports.
The Well Known Ports range from 0 through 1023.
The Registered Ports range from 1024 through 49151.
The Dynamic and/or Private Ports range from 49152 through 65535.
The Well Known Ports are assigned by the IANA, and on most systems, can only be used by
system processes or by programs executed by privileged users. The following table shows famous
port numbers among the well-known port numbers. For more details, please visit the IANA
website at http://www.iana.org/assignments/port-numbers.
TCP Socket
Application Service
0 reserved
1
TCP Port Service Multiplexor
2 Management
Utility
7 Echo
9 Discard
11 Active
Users
(systat)
13 Daytime
15 Netstat
20
FTP data port
21
FTP CONTROL port
23 Telnet
25
SMTP (Simple Mail Transfer Protocol)
37
Time (Time Server)
42
Host name server (names server)
