The value of vRtrMplsLspPathOperLeastFill indicates whether the currently operational LSP path was computed with the least-fill path selection method. When make-before-break functionality for the LSP is enabled and if the LSP least-fill setting is changed, the resources allocated to the existing LSP paths will not be released until a new path with the new settings has been established. While a new path is being signaled, the administrative value and the operational values of the path may differ. The value of vRtrMplsLspLeastFill specifies the least-fill setting for the new LSP path trying to be established whereas the value of vRtrMplsLspPathOperLeastFill specifies the least-fill setting for the existing LSP path.