A route discovered between a source node and destination
node is maintained as long as needed by the source node.
Since there is movement of nodes in mobile ad hoc network
and if the source node moves during an active session, it can
reinitiate route discovery mechanism to establish a new route
to destination.
Conversely, if the destination node or some intermediate
node moves, the node upstream of the break initiates Route
Error (RERR) message to the affected active upstream
neighbors/nodes. Consequently, these nodes propagate the
RERR to their predecessor nodes. This process continues
until the source node is reached. When RERR is received by
the source node, it can either stop sending the data or
reinitiate the route discovery mechanism by sending a new
RREQ message if the route is still required.