Users Manual

B
B. Well-Known Port Numbers
Listed below are Well-Known Port Numbers that may cause network problems if they are assigned to an
NPort serial port. Refer to RFC 1700 for Well-Known Port Numbers or refer to the following introduction from
IANA.
The port numbers are divided into three ranges: Well-Known Ports, Registered Ports, and Dynamic and/or
Private Ports.
• Well-Known Ports range from 0 through 1023.
• Registered Ports range from 1024 through 49151.
• Dynamic and/or Private Ports range from 49152 through 65535.
The Well-Known Ports are assigned by 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 Simple Mail Transfer Protocol (SMTP)
37 Time (Time Server)
42 Host name server (names server)
43 Whois (nickname)
49 Login Host Protocol (Login)
53 Domain Name Server (domain)
79 Finger protocol (Finger)
80 World Wide Web HTTP
119 Network News Transfer Protocol (NNTP)
123 Network Time Protocol
213 IPX
160 to 223 Reserved for future use