1. A method, comprising: receiving, at a node, a request to initiate a shadow joining operation to shadow join a field area router (FAR) of a computer network; preserving data structures and soft states of the node; initiating the shadow joining operation to shadow join the FAR, wherein shadow joining comprises preforming join operations without leaving a currently joined-FAR; measuring one or more joining metrics of the shadow joining operation; and reporting the one or more joining metrics.