ADVPN and shortcut paths

This topic provides an example of how to use SD-WAN and ADVPN together.

ADVPN (Auto Discovery VPN) is an IPsec technology that allows a traditional hub-and-spoke VPN’s spokes to establish dynamic, on-demand, direct tunnels between each other to avoid routing through the topology's hub device. The primary advantage is that it provides full meshing capabilities to a standard hub-and-spoke topology. This greatly reduces the provisioning effort for full spoke-to-spoke low delay reachability, and addresses the scalability issues associated with very large fully meshed VPN networks.

If a customer's head office and branch offices all have two or more internet connections, they can build a dual-hub ADVPN network. Combined with SD-WAN technology, the customer can load-balance traffic to other offices on multiple dynamic tunnels, control specific traffic using specific connections, or choose better performance connections dynamically.

Note

SD-WAN load-balance mode rules (or services) do not support ADVPN members. Other modes' rules, such as SLA and priority, support ADVPN members.

This topic covers three parts:

  1. Configure dual-hub ADVPN with multiple branches.

  2. Configure BGP to exchange routing information among hubs and spokes.

  3. Configure SD-WAN on spoke to do load-balancing and control traffic.

Configuration example

A typical ADVPN configuration with SD-WAN usually has two hubs, and each spoke connects to two ISPs and establishes VPN tunnels with both hubs.

This example shows a hub-and-spoke configuration using two hubs and one spoke:

  • Hub1 and Hub2 both use wan1 to connect to the ISPs and port10 to connect to internal network.

  • Spoke1 uses wan1 to connect to ISP1 and wan2 to connect to ISP2.