The value of the object vRtrSingleSfmOverloadAdminState specifies
the administrative state of the IGP single-SFM-overload
behavior in this virtual router instance.
When the value of vRtrSingleSfmOverloadAdminState is
equal to 'inService', IGP protocols (either IS-IS or OSPF) enter an
overload state when the node only has a single SFM functioning.