Single-Homed Full Mesh Gives HA Without Extra WAN Links

Design high availability for enterprise WAN for on-premises, hybrid, and cloud solutions
Answer Correct answer: B — One WAN interface per router means single-homed; a full mesh over the WAN service gives path diversity and high availability without extra WAN links.

Refer to the exhibit. Due to budget constraints, a customer decided to purchase WAN routers with one LAN and one WAN interface per device. There is a requirement to connect the three sites to ensure high availability without buying additional WAN links. Which design deployment must the customer choose? - image

  1. dual-homed full mesh
  2. single-homed full mesh Correct Answer
  3. single-homed hub-and-spoke
  4. dual-homed hub-and-spoke

Community Votes

B
56%
C
44%

56% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Community Insight

One WAN interface per device = single-homed. A full mesh over the WAN transport provides backup paths logically; dual-homed (A/D) would need extra WAN links the budget forbids.

Each router has only one WAN interface, so the sites are single-homed to the WAN service. Running a full mesh over that service provides any-to-any connectivity and logical path diversity, delivering high availability without purchasing additional WAN links (which dual-homing would require).

Picking C (hub-and-spoke): it has a single point of failure at the hub and less path diversity than a full mesh; the requirement for HA with backup paths points to full mesh (B), not hub-and-spoke.

Community Discussion (4 comments)

chaba7654321 👍 1 Selected: B
Agree with 935608e
935608e 👍 4 Selected: B
One WAN-Link -> Single homed No hub location defined -> full mesh Full mesh does not create additional cost
Swiz005 👍 2 Selected: C
Definitely C - There is budget constraints
Seb82 👍 2 Selected: C
I cannot see how D is an option, considering that each router has only one LAN and one WAN port

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Expert Analysis

Why the Answer Is Correct

B is correct. The one WAN interface per device means each site is single-homed to the provider. A full mesh over the WAN service yields any-to-any reachability and logical path diversity, so high availability is achieved without procuring extra WAN links.

Why the Other Options Are Wrong

A and D (dual-homed) require additional WAN links, which the budget constraint rules out. C (hub-and-spoke) creates a hub single point of failure and less path diversity than the full mesh the HA requirement implies.

Community Comment Notes

The vote is B (56) vs C (44). The top comment notes one WAN link means single-homed, and with no defined hub a full mesh adds no extra cost while meeting HA.

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