App-11
Appendix 4 TCP and UDP Port Numbers
The TCP and UDP port numbers that are used on the Ethernet interface of the instrument are listed below.
TCP Port Numbers
Port Number Description Used For
20 File Transfer [Default Data] FTP server, FTP client*
21 File Transfer [Control] FTP server, FTP client
25 Simple Mail Transfer Protocol SMTP client
515 − LPR client
111 −
Instrument control through the Ethernet interface1024 −
1025 −
UDP Port Numbers
Port Number Description Used For
67 Bootstrap Protocol Server DHCP client
68 Bootstrap Protocol Client (listen port)
111 − Instrument control through the Ethernet interface
123 Network Time Protocol SNTP client
* The port number when FTP passive mode is disabled. When FTP passive mode is enabled, you can set any
port number. When FTP passive mode is disabled, connections are established from the server. If you are
connecting the instrument from behind a firewall, enable FTP passive mode.
Appendix