I found the ns 2.31 patch for the FHMIP
Please show the download link for the patch
( For other LQ members interested in ns2 / FHMIP ).
And : You can easily have 2...5 different ns-allinone-2.xx installled
at the same time:
But do not add any of them to the PATH , LD_LIBRARY_PATH.
Usually not required since ns-2.26.