Use the crsctl pin css command to pin many specific nodes. Pinning a node means that the association of a node name with a node number is fixed. If a node is not pinned, its node number may change if the lease expires while it is down. The lease of a pinned node never expires.
You can specify a space-delimited list of servers
Any pre-12c release 1 (12.1) Oracle software must reside on a pinned server.
A node may be unpinned with crsctl unpin css.
Deleting a node with the crsctl delete node command implicitly unpins the node.