easyMultiple Choice
350-401 Practice Question: An enterprise is deploying Cisco SD-WAN with…
An enterprise is deploying Cisco SD-WAN with multiple vSmart controllers for redundancy. The engineer configures the vEdge routers to connect to two vSmart controllers. After deployment, the engineer notices that the vEdge routers are only connected to one vSmart, and the second vSmart is not being used. The vEdge routers show that the second vSmart is reachable. What is the most likely reason for this behavior?
⚠ Common exam trap
Cisco often tests the misconception that multiple vSmart controllers are used for load balancing or concurrent connections, when in fact they are strictly for active/standby redundancy, and a vEdge will only ever hold one active control connection at a time.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The vEdge routers are designed to use only one vSmart at a time; the second is for redundancy.
In Cisco SD-WAN, vEdge routers are designed to establish a control connection to only one active vSmart controller at a time, even when multiple vSmart controllers are configured for redundancy. The second vSmart serves as a standby; the vEdge will fail over to it only if the primary vSmart becomes unreachable. Since the vEdge shows the second vSmart is reachable but not actively used, this confirms the expected behavior of active/standby redundancy rather than load balancing.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The vEdge routers are designed to use only one vSmart at a time; the second is for redundancy.
Why this is correct
The vEdge router is designed to establish an OMP session with a single active vSmart controller at any given time, while concurrently maintaining DTLS/TLS tunnels to additional vSmart controllers for redundancy. The active vSmart processes all route exchanges and policy decisions; the backup vSmart remains in a standby state, ready to assume control automatically if the active vSmart fails. This active/standby model ensures control-plane continuity without requiring manual intervention or reboots.
- ✗
The vEdge routers can only connect to one vSmart at a time.
Why it's wrong here
This statement is false because a vEdge router can concurrently maintain control-plane connections (e.g., DTLS/TLS) to multiple vSmart controllers simultaneously, typically up to ten, for redundancy and high availability. While only one of those vSmarts is selected as the active OMP peer at a given time, the vEdge keeps the other sessions established and alive. Therefore, the limitation is not on the ability to connect, but on the number of vSmarts used for active OMP processing.
- ✗
The vEdge routers need to be rebooted to establish a connection to the second vSmart.
Why it's wrong here
A vEdge router does not need to be rebooted to establish a connection to a second vSmart; instead, the failure of the active vSmart triggers an automatic failover to a backup vSmart, which is already present in the network. The vEdge continuously monitors its control-plane connections and will initiate a new OMP session with a backup vSmart using the existing DTLS/TLS tunnel, completing the switch in seconds without any device restart. This design is critical for maintaining control-plane resilience and avoiding unnecessary downtime.
- ✗
The second vSmart has a different site ID than the first.
Why it's wrong here
This statement is incorrect because the site ID is a logical identifier assigned to vEdge routers (and sometimes other devices) to group them by geographic location for policy creation and segmentation, and it does not influence vSmart connectivity. vSmart controllers themselves are typically not assigned site IDs in the same way, and even when they are, the site ID has no bearing on which vSmart a vEdge selects as its active controller. The active vSmart selection is determined by control-plane preferences, reachability, and configured priorities, not by site ID.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 350-401 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-401 exam.