B
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 the IE-CS(T)-2TX-xRS232/485 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 are those from 0 through 1023.
The Registered Ports are those from 1024 through 49151.
The Dynamic and/or Private Ports are those 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:
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)
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 – 223
Reserved for future use
