A customer has several remote sites connected with their headquarters through microwave links. An engineer must propose a backup WAN solution based on these conditions:

Which backup WAN link type the engineer recommend?

Which QoS feature responds to network congestion by dropping lower priority packets?

A customer's current Layer 2 infrastructure is running Spanning Tree 802.1d, and all configuration changes are manually implemented on each switch. An architect must redesign the Layer 2 domain to achieve these goals:
reduce the impact of topology changes
reduce the time spent on network administration
reduce manual configuration errors
Which two solutions should the architect include in the new design? (Choose two.)

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?

A network administrator is troubleshooting a DMVPN setup between the hub and the spoke. Which action should the administrator take before troubleshooting the IPsec configuration?