I've tried to dig on Cisco.com website about this but all information leads to "ip forward-protocol udp" which helps the dhcp process (in-short). While I'm actually looking the proper explanation for "ip forward-protocol nd" I only got that parameter "nd" is used for old SUN network disk which I have no idea whether that still in use in current civilization. What is this command for and what is exactly Sun network disk?
This is an interesting explanation with good information about forwarding broadcasts. But it fails to address the question that David asks which is about forward-protocol "ND"
David - I doubt that there is any nd protocol in most networks these days. As far as I know it is a very old and deprecated protocol, and I doubt that you need to have much concern about it.
I suspect that your question arises from the fact that this command appears in your running config - but you did not enter it. I have noticed that in a lot of versions of 12.4T (and perhaps some others) this command is showing up. We did not input it, but it is showing up. It is showing up in running config because IOS chooses to show it. I do not have a good explanation for why it is showing up suddenly. But I am not sure that you can remove it. And I am sure that it is not doing any harm when it does show up.