dear all,
i just upgraded to ros 4.6 on rb450g, it seemed the check gateway ping on /ip routes of a pptp connection seemed didn’t work out pretty well.
by looking at the pptp interface status, the thing kept idle the same amount of time since it was connected. it didn’t happen before while using the ros 3.30.
the need of not being idle is to avoid disconnected from my supplier server if its idle for more than 10 minutes.
i believe this is a bug. i’m downgrading it to 3.30 again. hope this will be solved in the next version. keep up the good work! 
/chrone