text: can i telnet into a unix machine that is in the single user mode (init1)?   the other answerers are correct that the networking stack isn't functional in single user mode; however, there is something similar that you might consider.  in many server rooms, it's common to install a terminal concentrator that connects to the serial ports of multiple machines.  in that situation, you "telnet" to the terminal concentrator and open the connection to the serial port of the machine in question.  if the console has been redirected to the serial port, then you're in business.  a similar solution which avoids the need for a terminal concentrator is to connect the serial port of a machine to the serial port of a second machine via a  cross-over rs232 cable.  then you can "tip" from one machine to the other.  finally, on newer machines (well, typically "servers"), it's becoming common for there to be a "service processor" to provide "lom" (lights out management).  if this is available, you telnet to the service processor (which has a distinct ip address from the rest of the system) and it will have the capability to take over the console.  not sure if this answers your question, but it seemed like it might be related to the problem you might be trying to solve.