When designing an ADVPN (Auto-Discovery VPN) network for a large enterprise with spokes that have varying numbers of internet links, the main challenge is to minimize the number of peer connections and routes at the hub while maintaining scalability and efficiency.
Using a dynamic routing protocol (such as BGP or OSPF) with loopback interfaces helps in several ways:
- Reduces the number of peer connections at the hub by using a single loopback address per spoke instead of individual physical interfaces.
- Enables simplified route advertisement by dynamically learning and propagating routes instead of manually configuring static routes.
- Supports multiple internet links per spoke efficiently, as dynamic routing can automatically adjust to the best available path.
- Allows seamless failover if a spoke's internet link fails, ensuring continuous connectivity.