Configuring DMVPN Phase 1 w/ OSPF

In this blogtorial, we will configure DMVPN Phase 1 with OSPF and walk through some gotchas and some pitfalls to be on the look out for.

Due to the hierarchical nature of OSPF and other adjacency intricacies, OSPF is generally discouraged in a DMVPN design. 

We are using the same topology as my previous blogtorial "Configuring DMVPN w/ IPSEC and EIGRP", however I'll post the base configs here as well. 

Here is our topology. 

Configuring DMVPN Phase 1 w/ IPSEC and EIGRP

In this blogtorial we will take a look at how to configure DMVPN, EIGRP over DMVPN and get the traffic going over the DMVPN encrypted using IPSEC. We will break the blogtorial in 3 parts. First we will configure the DMVPN / tunnel and verify end-to-end IP connectivity, then we will move on to configuring routing over the tunnel and finally get IPSEC configured to encrypt everything going over the tunnel.

Here is our topology.

Configuring IPSEC VTI (Virtual Tunnel Interfaces)

In this blogtorial, we will briefly explore how to configure IPSEC Virtual Tunnel Interfaces. One of the main advantages of Virtual Tunnel Interfaces is that you do not have to configure an ACL to match all "interesting traffic", thereby minimizing the number of IPSEC security associations (SAs) that must be created.

We'll use the same simple topology from my previous blogtorial "Configuring GRE over IPSEC w/ Routing".