Re: [Roll] RPL clarification needed: moving down the DAG

[Richard Kelsey <richard.kelsey at ember.com>]

   Date: Wed, 4 Nov 2009 17:32:05 -0600 (CST)
   From: Mukul Goyal <mukul at uwm.edu>

   2. Now, lets suppose that new parent (B) has a higher rank than the
   node's current rank and is infact in the node's sub-DAG. The node (A)
   chooses it as a parent and consequently increases its rank. Now, we
   have a routing loop. [...] We will have "count to infinity" situation only
   when nodes in the loop are isolated from rest of the network. In that
   case, they will do "count to infinity" and produce lot of DIOs but we
   should not really care about these nodes (and their DIOs) since they
   are isolated any way.

Hi Mukul,

Remember that there may be multiple DAG instances.  Being
isolated from one DAG root does not mean that a node has
nothing useful to do.  It may just mean that it will use
a different DAG for the moment.
                                     -Richard Kelsey