The MDS tries to identify devices that FLOGI into it by doing a PLOGI back to the device. If the PLOGI is successful, it will then PRLI and issue a
SCSI inquiry command to see what the device is and what capabilities it has. If the PLOGI is rejected, then the MDS stops the discovery process. Some arrays reject the PLOGI due to lun masking, and it's up to the hosts to discovery what the array capabilities are. Did you by chance install one of the SSM or MSM line cards at the same time? I know that if one of these 'intelligent' line cards is installed, the MDS might be more agressive in trying to discover what devices are installed to permit provisioning of the advances features like SAN tap and other intelligent applications.
Hopefully this should not be causing any functional impact, if it is let us know and we can investigate further.
Mike
