A.2 Serial Console

fli4l can be used without monitor and keyboard. A drawback of this setup is that eventual error messages will not get noticed because not all messages can be piped to the syslog-port.

A possible solution is redirecting of all console messages to a PC or a classic terminal using the serial port of the router. Configuration is done by the variables SER_CONSOLE, SER_CONSOLE_IF and SER_CONSOLE_RATE.

Machines with older mainboards/cards don not support higher serial speeds than 38400 Bd. This is why you should try with a maximum of 38400 Bd at first before testing higher port speeds. Since only text messages are displayed on the console higher speeds are not evne necessary.

All messages that usually would go to the console are now redirected to the serial port - also messages of the boot process!

As a cable to the terminal or PC with terminal emulation a Null Modem Cable is used. Using a standard null modem cable is discouraged because these have bridges on the handshake wires. If Terminal or PC are powered off (or no terminal emulation is loaded) the use of a standard null modem cable can thus lead to a hangup.

This is why a special wiring is needed here for using fli4l also when the terminal is deactivated. You need a 3-wire cable, with some bridges on the plug. See Nullmodemkabel.