I'm using an MTS2EA to connect a serial device to our internal LAN. It functions correctly until I terminate the telnet session. Then the MTS2EA and the serial device begin talking to each other and my serial device is overwhelmed and shuts down.


The serial device I need to connect to responds to a valid DTR signal with several lines of data (such as device name, time, date, etc.) followed by a username and password prompt. When I connect to the serial device over ethernet, everything works fine. When I terminate the telnet session, however, the MTS2EA and the serial device begin talking to each other. Each device is expecting a login, and since my serial device transmits several lines of data, the MTS2EA responds to it as an invalid login, which causes my serial device to respond to the MTS2EA as an invalid login, etc. etc. This continuous exchange eventually overwhelms my serial device, and it shuts down. As soon as I connect through telnet to the serial device again, it returns to normal operation. It appears that any characters generated by the MTS2EA after the serial port is closed will cause my serial device to respond infinitely.


Use these commands to fix this problem:

- set login disable
- set serial s0 auto-dialin trig-mode char
- set serial s0 login-string "connect"
- save

With these commands, you will not see any login prompt unless the serial device sends out the word "connect" (without quotes).