In my previous blog entry, I found a tool MultiCom that proxies my serial to a TCP socket, but it was lacking the ability to set my telnet client into character mode and wasn’t working with Cisco devices.
I later found out this was because Telent sends CR + NULL everytime you hit ENTER, so this happens:
Username: (type username) CR Password: NULL (type password)
I couldn’t log in! I am curious why other devices ignored the NULL while Cisco choose to process it. Not as if NULL would be used as part of a password.
So, I got my script to work. Theoretically this script should work on any UNIX system and on any type of FIFO, but I’ve only had time to test it on the Mac and a serial cable.
Download the script here. Rename it to script.py and then chmod 755 script.py.

