IMS shutdown and RNR

When IMS is shut down using the MVS MODIFY command for IMS, RNR quickly terminates the IMS network, and VTAM® persistence is retained.

After the /START DC command is issued, IMS then automatically reconnects all sessions specified with ARNR that were still active at ABEND; sessions that were specified with NRNR are terminated.

When IMS is shut down using the /STOP DC command followed by the /CHECKPOINT command, VTAM terminals are disconnected for each session, resulting in no automatic session reconnect following an IMS restart.