300-415 Question 174
Single answerYou are tasked with configuring a control policy in a Cisco SD-WAN deployment to prefer specific WAN transport links for data traffic between branch sites. The policy should ensure that traffic between Site A and Site B always uses MPLS unless it becomes unavailable, in which case it should failover to the Internet link. Which step is essential for ensuring that this policy is applied correctly?
- A
Define a topology policy within the control policy and specify route preferences.
- B
Create a localized data policy with match conditions for MPLS traffic.
- C
Apply the control policy to the OMP routing process at the vSmart controller.
- D
Configure an application-aware routing policy on the branch routers.
Show answer and explanation
Correct answer: C
Explanation
To configure a control policy that ensures specific WAN transport preferences, the policy must be applied to the OMP routing process on the vSmart controller. This allows the vSmart controller to advertise the appropriate routes with the desired preferences to the edge routers. Other options, such as data policies and application-aware routing, operate at the data plane and do not influence control plane routing decisions.
- A. Incorrect.
Defining a topology policy is incorrect because you cannot directly control traffic failover behavior using topology definitions. Control policies are used for route manipulation, not defining topologies.
- B. Incorrect.
A localized data policy is designed for modifying data-plane traffic forwarding decisions and does not impact the control plane's route advertisement or failover preferences.
- C. Correct.
Applying the control policy to the OMP routing process at the vSmart controller is correct because control policies influence route advertisements and preferences, ensuring that specific transport links are preferred.
- D. Incorrect.
Application-aware routing policies are used to dynamically steer traffic based on performance metrics, but they do not affect control plane routing preferences or failover mechanisms.