The value of vRtrMplsP2mpInstAdaptive specifies whether make-before-break functionality is enabled. If the value of vRtrMplsP2mpInstAdaptive is set to 'true', it enables make-before-break functionality for the P2MP LSP. When the attributes of an already established P2MP LSP are changed, either through manual configuration or due to a change in network topology, make-before-break functionality ensures that the resources of the existing P2MP LSP will not be released until a new path (with the same P2MP LSP Id) has been established and traffic flowing over the existing path is seamlessly transferred to the new path. If the value of vRtrMplsP2mpInstAdaptive is set to 'false', it disables make-before-break functionality.