System event broadcast synchronization across hierarchical interfaces

Aspects of the invention include computer-implemented methods, systems, and computer program products that assign a centralized event tag to each communication interface of a plurality of communication interfaces of a chip interconnected in a hierarchy through the communication interfaces to a plurality of chips in a multiprocessing system. A determination is performed of whether to accept or drop a message associated with an event received at one of the communication interfaces of the chip based on comparing a local centralized event tag with a received centralized event tag. The local centralized event tag is updated based on one or more advancing rules to maintain event synchronization between the chip and the plurality of chips.