Question: Can I telnet into a UNIX machine that is in the single user mode (init1)? 

Answer: The other answerers are correct that the networking\nstack isn't functional in single user mode; however,\nthere is something similar that you might consider.\n\nIn many server rooms, it's common to install a terminal\nconcentrator that connects to the serial ports of\nmultiple machines.  In that situation, you "telnet"\nto the terminal concentrator and open the connection\nto the serial port of the machine in question.  If\nthe console has been redirected to the serial port,\nthen you're in business.\n\nA similar solution which avoids the need for a terminal\nconcentrator is to connect the serial port of a machine\nto the serial port of a second machine via a \ncross-over RS232 cable.  Then you can "tip" from one\nmachine to the other.\n\nFinally, on newer machines (well, typically "servers"),\nit's becoming common for there to be a "service processor"\nto provide "LOM" (lights out management).  If this\nis available, you telnet to the service processor (which\nhas a distinct IP address from the rest of the system)\nand it will have the capability to take over the\nconsole.\n\nNot sure if this answers your question, but it seemed\nlike it might be related to the problem you might be\ntrying to solve.
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