When a dynamic VIPA is defined using VIPADEFINE on one TCP/IP, and other stacks are designated as backup using VIPABACKUP statements for the same dynamic VIPA, the stack with the highest backup rank for that DVIPA will activate it if or when the VIPADEFINE stack fails.
If the failed stack is later restarted with the same VIPADEFINE profile statement, it is likely that connections to that DVIPA will exist on the backup stack that now has the DVIPA activated and advertised to the routers. How and when ownership of the DVIPA is returned to the restarted stack is determined by how the DVIPA was originally configured.