I am planning to perform head upgrade from fas8020 to fas8300. but cluster ports in fas8300 are 100GbE but fas8020 are 10GbE.
I checked old posts and found the same question and post owner asked to use ha interconnect port which is support 10GbE. (https://community.netapp.com/t5/ONTAP-Discussions/arl-from-a300-to-a400/m-p/159922) My question is same but I am wondering there is no information about this issue. The KB I'm using, is saying fas8020 support upgrade to fas8300 but the is no additional information about this. (For example; fas8020 to fas8300 can temporarily use ha interconnect for cluster connection)
your suggestion make sense but in my demo environment I had problem about cluster ports.
In demo env, I upgraded from fas8020 to fas2552(no internal drive) but one controller completing without problem. After ı select options 6 ( Update flash from backup config), I modify new cluster ports and then migrate cluster lif to new cluster port with no problem. But in second node ı also modied cluster port but when I checked lifs, output just show management lif. I tried to use migrate but it gave error.
After some diggig ı found another solution. before I halt second old node, modfiying cluster port which exists on new node. After then when I attached the cable and boot new node, it is opening with that config and has no problem to connect cluster.
At the end why ı want to use ha interconnect(e0a and e0b) in Fas8300 for cluster port, because it is same cluster port in fas8020(e0a and e0b).