If diag-switch? is set to true and you use the bootmode -u command to reboot your workstation, rsc-console will revert to the serial (tip) connection after Solaris restarts, even if you have previously redirected the console to RSC.
If this occurs, manually redirect the console ouput to RSC again after the reboot operation has completed. Refer to the Sun Remote System Control (RSC) 2.2 User's Guide for more information.