VIPADEFINE MOVEABLE WHENIDLE

If an IPv4 DVIPA was originally configured with MOVEABLE WHENIDLE, the following events occur:

• If it appears that there are no active connections to the DVIPA on the backup stack:
  • The DVIPA is removed from the HOME list on the backup stack and reverts to backup status.
  • The restarted stack assumes ownership of the DVIPA by adding it to its HOME list and notifying the routers.
• If there are existing connections to the DVIPA on the backup stack:
  • Ownership of the DVIPA remains with the backup stack. The DVIPA on the restarting stack is placed in backup status at the head of the backup list for the DVIPA.
  • The backup stack periodically checks to see if it has any active connections to the DVIPA.

    When or if it appears that there are no active connections for the DVIPA, the following events occur:

    • The DVIPA is removed from the HOME list on the backup stack and reverts to backup status.
    • The restarted stack assumes ownership of the DVIPA by adding it to its HOME list and notifying the routers.
    Notes:

    1. WHENIDLE is supported only for IPv4 DVIPAs.
    2. A small period of time exists between the check for connections and the movement of the dynamic VIPA to the restarted stack. If connections are made to the old host (the backup stack) in this interval, they will be broken.
    3. During the time that TCP/IP is periodically checking for connections, TCP/IP does not refuse new connections because this would be the same as an outage. If moving the work back to the restarted stack is more important than maintaining uninterrupted service to all clients, then the system operator can use the VARY TCPIP,,OBEYFILE command to delete the dynamic VIPA on the backup stack with the VIPADELETE profile statement. This causes the restarted stack to immediately activate the DVIPA. Optionally, the data set specified on the command can contain a VIPABACKUP statement following the VIPADELETE statement. This will restore the stack as a backup stack.