The common problem which Cisco newbie’s face is that how to see debug console messages on telnet prompt. I have been asked this question for multiple times, not only from my juniors but also sometimes from my peers.
Command is “terminal monitor”. By enabling this command, all your console messages can be seen on a telnet session. But a word of caution here, if ever you enable terminal monitor, never forget to turn it off. Otherwise every time you will telnet that router/switch, you will see console messages coming on your telnet screen and sometimes these are quiet annoying.