15.26 Connections are not Getting Established if a Cluster Resource is Migrated from OES 2015 or Later to OES 11 SP2 Node

Description: In a mixed-node cluster environment, that is, OES 2015 or later nodes and the nodes running earlier versions of OES (OES 2 SP3, OES 11, OES 11 SP2), if you migrate a cluster resource from OES 2015 or later to earlier versions of OES, the existing connections accessing that resource might not establish automatically.

Cause: The client maintains a runtime cache for each server with which it communicates, whose cached entry indicates the protocol supported by the server.

When a cluster resource is on an OES 2015 or later node, the client maps the resource using SMB 2 protocol. If the same resource is migrated to earlier versions of OES, the client assumes that this server is also SMB 2 protocol capable and without negotiating with the server attempts to reconnect using SMB 2, which the node rejects since it's not SMB 2 protocol capable.

Action: To resolve this problem, the user must login to the server running earlier versions of OES afresh to access the resource. When doing a fresh mapping, the client first enumerates and negotiates the server's capability and then connects using the highest protocol that the server is capable of.