DMVPN - What is the best routing protocol to use

When deploying a DMVPN topology, there are several choices for the use of a routing protocol to share the routes behind the spokes and the hub. The choice of routing protocol depends on several factors.

The choice of routing protocol depends on the specific network requirements and design. Generally speaking, OSPF is typically avoided when it comes to DMVPN due to its strict design hierarchy.

Both EIGRP and BGP are good choices for a DMVPN environment and both are often used.

EIGRP has advantages like faster convergence and simplicity in configuration, but it’s a Cisco proprietary protocol and might not be the best choice if you’re considering a multi-vendor environment. It also works well in small to medium-sized networks.

BGP, on the other hand, is more complex to configure and has slower convergence, but it’s highly scalable and works well in larger networks. It’s also vendor-neutral and offers more granular control over routing updates.

If you choose BGP, using iBGP with dynamic peers is indeed a good option for DMVPN. This setup allows for more flexibility and scalability, as it can accommodate a large number of spokes without needing to manually configure each peer relationship.

If your network is small to medium-sized and primarily Cisco, EIGRP might be the best choice. If it’s a larger, multi-vendor network, or if you need more control over your routing updates, BGP would likely be the better option.

That’s not to say that OSPF should never be used. Many organizations have used it successfully, however, with the appropriate care, planning, and design needed to ensure correct operations.