Which port need to open among CS, MA and VSAProxy to take Openstack Backup

Make sure to always have these ports (8400/8403/8401) open as they are used by CV.

Review the Requirements for OpenStack

System Requirements for Virtual Server Agent with OpenStack

https://documentation.commvault.com/commvault/v11/article?p=3349.htm

Port Requirements

• The security group associated with the proxy instance should permit all incoming and outgoing TCP traffic.
• If unrestricted access cannot be set up, configure a one-way Commvault firewall between the CommServe host or MediaAgent and the VSA proxy instance. With this firewall configuration, you can restrict communication to a single TCP port (typically port 8400).

TCP Ports Used for Services

https://documentation.commvault.com/commvault/v11/article?p=8572.htm

Hope it helps.

By default, Commvault expects all ports to be open between Commvault components. You can tell it to force communication over a single port (default 8403) using network routes.