Aaarrrgggghhh, I hate it when I would like to telnet into a device and enter the wrong IP address. This means, by default, waiting for 30 seconds before being able to correct the IP address and start a new telnet session, because there is no escape sequence.
Trying 10.100.12.250 …
% Connection timed out; remote host not responding
Luckily there is a command to lessen the time for timing out the connection:
SW01(config)# ip tcp synwait-time <seconds> (Set time to wait on new TCP connections)
Hoera, tcp synwaiting saves the day….