I discovered that this question has been answered but, I tried to use the answers suggested by other people but they did not work out for me.
I tried to follow a tutorial, NS2: How to add new routing protocol, on http://elmurod.net/en/index.php/archives/157
The following error was produced
Makefile.in is new than Makefile, you need to re-run configure. False
Make: *** [Makefile] Error 1