Updating software in multiple adapter cards

A computer program product for updating software in a computer system, the computer system comprising at least a central processor and multiple adapter cards, wherein the adapter cards are attached to a network,

• the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by the computer system to cause the computer system to perform a method comprising:
• the central processor generating a distribution map based on configuration data of the network, the distribution map comprising an ordered structure of unique network identifiers of adapter cards that are to be updated with software update data;
• the central processor sending the software update data and the distribution map to a receiving adapter card of the adapter cards referenced in the distribution map;
• in response to receiving the software update data and the distribution map, the receiving adapter card,
• applying the received software update data;
• creating at least one modified distribution map by removing network identifiers including the identifier of the receiving adapter card from the distribution map such that the at least one modified distribution map comprises a disjoint subset of network identifiers from the distribution map;
• for the at least one modified distribution map sending the received software update data and the modified distribution map to at least one next adapter card in the modified distribution map.