The console port does not allow reverse connection, so "transport input" is not allowed. That command will work on all other lines, including the AUX port. The settings on the console will not affect the port async 0/3/0.
For a reverse telnet connection, you expect async 0/3/0 to be down/down; the async INTERFACE only comes active when you run a packet based protocol (e.g, PPP) on the async line. For character based connection, you look at the LINE, not the INTERFACE.
Look at "show line" to see what the line index number is for async 0/3/0. There is a line number reserved for each of the slot-port combos. The line number associated with async 0/3/0 will be what you put in the alias.
If you want an IP address associated with a port so you can telnet to a port, the command you want is "ip alias."
The port number 2xxx connects to port xxx, which you can see in the "show line" command.