Telnet options required to establish a Telnet connection.

Telnet options required to establish a Telnet connection.

The Network Component's Telnet server is configured to work with most of the available Telnet clients. If the connection fails, this may be because Telnet options are not agreed as required on the Telnet server. To establish a Telnet connection, the following Telnet options are negotiated:

• ECHO
• SUPPRESS-GO-AHEAD

If the Telnet negotiation reply does not match the required one, the Telnet server disconnects.

The Telnet server sends Telnet negotiation options that depend on the settings in the Telnet configuration, this is the configuration option Disable Echo:

• Disable Echo not active

  Send Command	Send binary	Required Reply	Reply binary
  IAC DO SUPPRESS-GO-AHEAD	255, 253, 3	IAC WILL SUPPRESS-GO-AHEAD	255, 251, 3
  IAC WILL SUPPRESS-GO-AHEAD	255, 251, 3	IAC DO SUPPRESS-GO-AHEAD	255, 253, 3
  IAC DON'T ECHO	255, 254, 1	IAC WON'T ECHO	255, 252, 1
  IAC WILL ECHO	255, 254, 1	IAC DO ECHO	255, 253, 1

  
  
• Disable Echo active

  Send Command	Send binary	Required Reply	Reply binary
  IAC DO SUPPRESS-GO-AHEAD	255, 253, 3	IAC WILL SUPPRESS-GO-AHEAD	255, 251, 3
  IAC WILL SUPPRESS-GO-AHEAD	255, 251, 3	IAC DO SUPPRESS-GO-AHEAD	255, 253, 3
  IAC DO ECHO	255, 253, 1	IAC WILL ECHO	255, 251, 1
  IAC WON'T ECHO	255, 252, 1	IAC DON'T ECHO	255, 254, 1