AZ-305 Practice Question 68: ExpressRoute Low Cost Backup
Microsoft Azure Solutions Architect Expert (AZ-305) · Test 7 · question 8 of 10
A company connects its datacenter to a hub virtual network with a single ExpressRoute circuit that uses private peering. The circuit is not geo-redundant. Leadership wants a low-cost way to keep private traffic flowing if the circuit fails, and does not want to buy a second circuit.
What should you add to the design?
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Answer:
For a single ExpressRoute circuit without geo-redundancy, a site-to-site VPN can serve as the backup for private peering. It can coexist with the circuit on the same virtual network. Route preference favors ExpressRoute while it is healthy, and traffic falls back to the encrypted VPN tunnel if the circuit is lost. It costs far less than another circuit.
Option A applies to Microsoft peering. Internet connectivity is a backup option for Microsoft peering traffic, not for private peering to virtual networks.
Option C would require a client connection from every server, which is unmanageable and does not offer a network-level backup for the datacenter.
Option D is a second circuit, which the requirement excludes on cost, and at the same peering location it would share the failure domain of the first.
Reference: Azure ExpressRoute: Designing for disaster recovery