"Reference : RFC 2863: The Interfaces Group MIB - ifType" . "The type of the interface.\n\nWhen an interface entry is created, a server MAY\ninitialize the type leaf with a valid value, e.g., if it\nis possible to derive the type from the name of the\ninterface.\n\nIf a client tries to set the type of an interface to a\nvalue that can never be used by the system, e.g., if the\ntype is not supported or if the type does not match the\nname of the interface, the server MUST reject the request.\nA NETCONF server MUST reply with an rpc-error with the\nerror-tag 'invalid-value' in this case." . . . . "This statement is mandatory." . . .