Solaris

do you know the pin-out of the serial cable?

The serial connection on newer Oralce/Sun hardware should only be used to configure the ILOM with an IP address. After that you should use SSH or https to connect to the ILOM through the netMgmt port! The serial line can still be used as a failsafe but should only be used with a terminal server.

Read here from page 32 onwards:
https://docs.oracle.com/cd/E19488-01...20-3800-13.pdf

and here for more infos about ILOM:
https://docs.oracle.com/cd/E19488-01...20-6588-12.pdf

The server is Sparc Enterprise T5440 running Solaris 10.
I have not had to reboot the windows machine since I posted. For now my solution is to avoid rebooting the windows machine. I will also look into setting up the management port, but if the existence of a serial connection (cable) itself somehow sends break signal to the server, it is a concern. I am also wondering if windows 10 somehow causes this (sends some signal to serial port during reboot).

Thank you all for your comments.

The problem is,
a classic terminal, when it is in a classic terminal application, and when you reboot, still thinks that you are in the terminal application. And you have problems to run shell commands.
Therefore, the classic method is to send a break=reset during the serial port initialization (reboot) so the command line works again.
Unfortunately the Sun-Sparcs have implemented the break=reset to halt(pause) the OS. And another Sun-Sparc will not send a hardware-break signal.
Sun and partners offered serial cables where the hardware-break signal is not wired, for the case a non-Sparc device (Windows, or a serial Terminal Server) sends the classic break=reset signal.
So you could use such a cable, or use my suggested fix for the kbd driver, or use an ssh connection to the console port (from Windows e.g. via putty.exe).

I will try what MadeInGermany suggested. great advise.
Thanks alot