Refer to the exhibit, which shows the ADVPN IPsec interface representing the VPN IPsec phase...

When configuring ADVPN (Auto-Discovery VPN) to connect overlay networks across different hubs using IBGP and EBGP, special configurations are required to allow spokes from different overlay networks to dynamically establish tunnels.

● set auto-discovery-crossover enable

● This allows cross-hub tunnel discovery in an ADVPN deployment where multiple hubs are used.

● Since Hub A and Hub B belong to different overlays, enabling crossover discovery ensures that spokes from one overlay can dynamically create direct tunnels to spokes in the other overlay when needed.

● set enforce-multihop enable

● This setting ensures that BGP peers using loopback interfaces can establish connectivity even if they are not directly connected.

● Multihop BGP sessions are required when using loopback addresses as BGP peer sources because the connection might need to traverse multiple routers before reaching the BGP neighbor.

● This is especially useful in ADVPN deployments with multiple hubs, where routes might need to cross from one hub to another.