After a rebuild, the EZBEPORT structure is repopulated using local data from each of the TCP/IP stacks. Each TCP/IP stack is notified that a rebuild has occurred, and the structure must be repopulated. Each TCP/IP stack sends updated information about the ephemeral ports VTAM® allocated to it to VTAM to be written to the EZBEPORT structure. During a rebuild, TCP/IP is not able to access the coupling facility. This creates a problem with obtaining ephemeral port numbers for new connections. Therefore, requests for connections involving new ephemeral port numbers fail during a rebuild. It is assumed that rebuild takes on the order of 10-15 seconds, and the requests for new ephemeral port numbers are satisfied when the rebuild and repopulate has completed. However, there are many factors which can affect the time for rebuild to complete, such as system load and number of structures being rebuilt. This situation is not likely, and it is rare that such a massive rebuild is required.