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 5110 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
TCP Socket | Application Service |
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0 | Reserved |
|
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1 | TCP Port Service Multiplexor |
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|
2 | Management Utility |
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|
7 | Echo |
|
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9 | Discard |
|
|
11 | Active Users (systat) |
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|
13 | Daytime |
|
|
15 | Netstat |
|
|
20 | FTP data port |
|
|
21 | FTP CONTROL port |
|
|
23 | Telnet |
|
|
25 | SMTP (Simple Mail Transfer Protocol) |
|
|
37 | Time (Time Server) |
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|
