Oracle RAC Behaviour when Public Network Fails on Both Nodes

Hello,

The setup is 2 nodes RAC with 19c Grid + 11g Database.

It is observed that when public network fails on one node, only network resources on that node fail over to the other node.

However, when public network fails on both nodes at the same time, one database instance is shutdown while the other instance is open.

I found from alert log that the instance was evicted by the other instance because they could not communicate to each other.

After public network was resumed, the evicted database instance was able to be manually started up.

From alert log:

Suppressed nested communications reconfiguration: instance_number 1