The SD-WAN Orchestrator Tech Note is an essential document to understand how DC redundancy works and includes several reference architectures:
https://www.arubanetworks.com/techdocs/central/sd-branch-ref-docs/sd-branch-orchestrator.pdf
Additionally, the Validated Solutions Guide expands on the topic of Hub designs as well:
https://www.arubanetworks.com/techdocs/VSG/docs/080-sd-branch-deploy/esp-sd-branch-deploy-040-configuring-vpnc/
There are some design differences whether you already leverage AOS 10 in your environment or still run 8.x code (that is EoST by end of 2023 by the way). AOS 10 allows you to configure VPNC clustering, where this is not yet possible with 8.x.
If you need assistance in the actual bring-up of the config, you might want to reach out to a local Aruba partner for assistance.
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I work for Aruba. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
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