Routing: OSPF routing inside GRE tunnels.
GRE tunnels inside IPSEC tunnels with OSPF routing.......
Ruben Püttmann commented
Carlos Serra commented
please keep in mind this idea not only OSPF routing
Samit Jana commented
This makes easier to do interop with Cisco who are using IPsec over GRE and doing OSPF routing for failover, like us.