You're welcome.
For your information, I will try to keep it simple.
7-mode [Which is known as HA Pair, non-clustered] : Is available until 8.2.x only, end of journey for 7-mode NetApp OS. [Data ONTAP 8.3 and later do not include a 7-Mode version]. This 7-mode version supports only SMB2.0 & 2.1 dialects. However, certain versions of "Linux" (Not Windows) as 'SMB Client' can only negotiate SMB1.0. Hence, if even if 7-mode is capable of negotiating SMB2.0/2.1, client fails to connect as we observed in the logs previously.
Cluster Data ONTAP: Until 8.3.x was called cluster Data ONTAP [Cluster-Mode], however since 9.x it is renamed to simply 'ONTAP'. Hence, what I had mentioned as 'cDOT/ONTAP', I was basically referring to 'Clustered Ontap', which we now call 'ONTAP'. In cDOT, since cDOT 8.2, higher SMB dialects are supported such as SMB2.0,2.1,3.0. I mean cDOT 8.2 and not 7-mode 8.2, and there is no 8.4 in either.
Following Linux 'kernel' as SMB Client and ONTAP 9.x as SMB Server works with SMB Dialects 1.0,2.0,2.1 & 3.0. Please note, I haven't tested all the kernels, but this was minimum Centos7 that I downloaded and tested and it seems to work.
[root@redhatcentos7 ~]# uname -a
Linux redhatcentos7 3.10.0-1062.el7.x86_64
Output from my 9.1P13 NetApp Simulator:
::> cifs session show -fields protocol-version,address
node vserver session-id connection-id address protocol-version
--------- ------- ---------- ------------- ------------- ----------------
cdot91-01 cifs 14047853137675419654
2157827681 192.168.0.39 SMB1
cdot91-01 cifs 14047853137675419656
2157827683 192.168.0.39 SMB2
cdot91-01 cifs 14047853137675419652
2157827677 192.168.0.39 SMB2_1
cdot91-01 cifs 14047853137675419654
2157827681 192.168.0.39 SMB3
Thanks!