Various embodiments provide a method for ascertaining a type of a gas discharge lamp using an electronic ballast for operating different types of gas discharge lamps, wherein the different types of gas discharge lamps differ in at least one operating parameter, wherein the method may include: a) preheating at least one filament in the gas discharge lamp for a predetermined preheating time; b) measuring a physical variable which is characteristic for the type of the gas discharge lamp at the end of the preheating time and providing the measurement value of said variable; and c) ascertaining the lamp type on the basis of the measurement value which is provided, wherein the preheating time is increased by a predetermined time period and the b) and c) are repeated if the lamp type in c) cannot be ascertained uniquely. Moreover, various embodiments provide an electronic ballast for operating at least two different types of gas discharge lamps which have at least one different operating parameter.