Yingyot,
In general, we do not document the "standard" platform independent routing commands in our tech docs. The command is supported on cat4500.
I tested the command you listed in lab; that is supported in Cat4500 switch.
Below, I have included the output for the ip forward-protocol global configuration command.
4507R-9(config)#ip forward-protocol ?
nd Sun's Network Disk protocol
sdns Network Security Protocol
spanning-tree Use transparent bridging to flood UDP broadcasts
turbo-flood Fast flooding of UDP broadcasts
udp Packets to a specific UDP port
HTH,Please rate if it does.
-amit singh
