After powering on Dell PowerEdge-based VxRail nodes, what defines the primary node of the cluster being configured?

A company has indicated that they do not want to change the native VLAN for their entire switch.
Based on best practice, how should the Top of Rack (ToR) switch be configured?

You are configuring a VxRail to connect to an existing, external SRS VE. The customer's support account is associated with the Site ID/Party ID where VxRail is installed. A validation error is issued when you attempt to register VxRail in SRS.
What is the possible cause for the error?

You want to deploy VxRail, leveraging your existing VMware SSO domain.
What is the recommended method?

An implementation engineer is validating a VxRail deployment of six V570F nodes, each with four 10 Gb connections. The VxRail nodes have not been powered on.
Which command should they run to confirm that the Dell EMC ToR switch is configured correctly?