Clustering in MANET

There is no ready-made / simple way to do clustering in MANET.
There are some sensor network extensions which contain some kind of clustering mechanism. But you can not simply use them the way in which you want. Further, as far as I know, in ns2, security aspects of the simulations were not considered in most of the simulations. The fact is, (according to my belief) implementing a real encryption or decryption in a simulator is beyond the scope of the simulator. Even security aspects also should be simulated in one way or another.

But, Qualnet seems to to be having some security aspects (like IPsec, RSVP).