SD-WAN with ADVPN 2.0 versus previous ADVPN
With the previous version of ADVPN and SD-WAN, shortcut path selection relied entirely on the overlays between the spokes. The hub and overlays were used to exchange IKE shortcut messages, and policy routes were configured on the hub to ensure shortcuts were established on the same overlay. In addition, user traffic was needed to trigger the process of establishing shortcuts.
With the latest version of ADVPN and SD-WAN, shortcut path selection is achieved through edge discovery and path management functionality on the ADVPN spokes.
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Edge discovery:
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Expand IKE Shortcut-Reply message to allow the local spoke (spoke where user traffic is initiated) to obtain the remote spoke (destination spoke for user traffic) WAN link information, which includes IP address, transport group, link quality, link cost, and member configuration order.
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After shortcut establishment, WAN link information can be exchanged on the shortcut regularly every 5 seconds through UDP traffic. The path management function on the local spoke is regularly updated to pick up changes to remote or local overlays and select the best shortcut path accordingly.
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Path management:
The local spoke handles the remote spoke WAN link information, calculates the best shortcut path per SD-WAN service or rule, and then advises IKE to establish a shortcut using the selected path.
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Currently, ADVPN 2.0 only supports IPv4. |