A few days ago we received about 40 Errors in about 30 seconds with the message:

7.4.3 iSCSI login to target ___from initiator ___ failed for the following reason:
7.4.42 Unexpected login failure code.

This was followed a few minutes later by:

28.3.29 Active control module cannot communicate with secondary control module. Failover cannot occur.
33.3.0 Communication link between control modules has shut down.
28.3.20 Control module was removed from array.
28.4.50 Control module in slot 1 is not functioning or not installed.

Within a minute of those messages, the control modules come back up and everything appears to be working properly again.  The installed firmware is version 7.1.7.  Does anyone have any ideas about what is at fault here and what needs to be done to address this?  Thanks.