Which solution allows overlay VNs to communicate with each other in an SD-WAN Architecture?

Which common issue causes intermittent DMVPN tunnel flaps?

A company must automate a set of complex changes aligned with DR testing in the network.
These changes are specific, and the DR playbook will be adjusted in the future. The playbook has diverse routing and switching assets in scope as well as multiple vendor and hardware platforms.
A developer will create a thin, web front-end microservice and integrate with an Open daylight controller to push changes to the network. Which YANG model should be used?

Which two Cisco ISE use cases typically involve the highest level of implementation complexity?
(Choose two.)

A company with multiple service providers wants to speed up BGP convergence time in the event a failure occurs with their primary link.
Which approach achieves this goal and does not impact router CPU utilization?