How to build ? The easiest to use is 'ns-allinone-2.33.tar.gz' (newest version)
It has no dependencies, get it here:
Unpack to /home/"user"/tmp and run command './install' (or 'sh install')
Compiles without problems on Fedora 8. Other Fedora's :
See also 'similar threads' (bottom of this and other LQ - pages).
To use ns2 : see addresses in 'README'