how to only enable some node to use multiPath?

["Guo, Liang" <guol@cs.bu.edu>]

Hi, 

I want to only enable some nodes in the network to be able to
use multiPath (while others are not), according to NS document,
I should do something like:

set n1 [$ns Node]
$n1 set multiPath_ 1

however, these doesn't work, seems that "multiPath_" setting
can only be applied to all or none. Is that true? 

If so, how to modify the code to enable patial "multiPath_" setting?

Thanks a  lot.

Guo, Liang.