[Planetlab-users] How can I use a node as router

[abakr at stevens.edu]

Hello All,
 
I am trying to set ip_forward value on a planetlab node using the 
command:   > sudo sysctl -w net.ipv4.ip_forward=1
 
But, I got this error;
   error: permission denied on key 'net.ipv4.ip_forward'
  
Can I set ip_forward value or not ? and why?
 
I need to use planetlab node as a router to forward data to next hops.
Are there other methods to route data thru Planetlab nodes ???

I need help please !!!
 
Regards,
 
Alam Bakr