Hi,
this may be caused because the hostname listed in the certificate does not match the actual hostname / FQDN of the cluster.
This may happen in case DNS settings or cluster name are changed post cluster setup.
I also wouldn't exclude the cluster setup logic to have a flaw so that hostname/FQDN of the cluster and the certificate don't match.
Please try to re-create the SSL certificate according to this KB article:
https://kb.netapp.com/support/index?page=content&id=1014389&actp=search&viewlocale=en_US&searchid=1474277936105
Although the article is written explicitely for ONTAP 8.1 and 8.2/8.3, please follow those steps outlined for 8.2/8.3 for ONTAP 9. They should be identical.
Then try adding the cluster to OCUM.
Kind regards, Niels
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