I want to forward all the Mavlink data I receive on Telem1 to Telem2.
In PX4 we can do it via editing the rcs file, and using -f option in mavlink start.
How can I do the same in Ardupilot.
Also is there any concept of rcs file in Ardupilot, if so which file refers to the startup functionality.
AP will auto forward messages that are not for its own SYSID. Its on by default but there is a option to turn it off in SERIAL_xOPTIONS (in 4.1.dev). Just set both ports to MAVLIink.