The connection between the SD-Routing branches and a public-cloud application is provided by an Azure VPN Gateway that is
configured inside the Azure Virtual WAN hub as part of Cloud OnRamp for Multicloud SD-Routing workflow for Azure.
The Cloud OnRamp for Multicloud flow in Cisco SD-WAN Manager discovers your existing VNets in geographical cloud regions and
allows you to connect select VNets to the overlay network. In such a scenario, Cloud OnRamp for Multicloud allows simple integration
between legacy public-cloud connections and the Cisco Catalyst SD-Routing network.
A configuration wizard in Cisco SD-WAN Manager automates the bring-up of the Azure Virtual WAN Hub to connect with your public
cloud account. The wizard also automates the connections between public-cloud applications and the users of those applications
at branches in the overlay network. Using tags, Cisco SD-Routing Manager enables you to map the service default-VRF in your
branches with specific VNets in your public cloud infrastructure.
VNet to VPN Mapping
The Intent Management workflow in Cisco SD-WAN Manager enables connectivity between Cisco SD-Routing default VRF (branch networks)
and VNets, and VNets to VNets. You can enable both SD-Routing and SD-WAN connectivity mapping. When you enable the SD-WAN
VPN, the SD-Routing VRF gets enabled by default. VNets are represented by tags created under the Discover workflow for Cloud
OnRamp for Multicloud. When you create VNet tags within an Azure region, mapping is automatically created based on the other
VNets and VPNs that share the same tag.
When Cisco SD-WAN Manager records the intent for connectivity, mapping is realized in cloud in regions where the cloud gateway
is present. Mapping intents can be entered without cloud gateways being present in different regions. Your mapping intent
is preserved and realized when a new cloud gateway or mapping change is discovered. As and when cloud gateways get instantiated
or discovered in different regions, the mapping intents are realized in those regions. Similarly, tagging operations can influence
the mapping in different regions as well and mappings as per the tags are realized in the cloud.