AZ-305 Design infrastructure solutions Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Azure Front Door

  Why it's wrong here

  Azure Front Door is an application delivery and global load-balancing service that accelerates HTTP/HTTPS traffic using Microsoft's edge network. It can route traffic away from a failed primary endpoint, but it performs no block-level or volume-level data replication of Azure Managed Disks and has no awareness of VM state. To meet the RPO requirement, the VM disks would still need continuous replication underneath, which Front Door does not provide; it only influences incoming client traffic after an endpoint is marked unhealthy.

• ✗

  Azure Backup

  Why it's wrong here

  Azure Backup is a data-protection service that creates periodic snapshots and stores them in a Recovery Services vault, with VM backup frequency often limited to one snapshot per day and an RPO that can be many hours depending on the policy. Restoring a full VM from a backup typically requires creating a new VM from the restored disk and can take tens of minutes or longer, which far exceeds a low-RTO target. While backup complements Site Recovery, it is not architected for near-synchronous replication or for the automated, orchestrated failover between regions that a critical workload requires.

• ✗

  Azure Traffic Manager

  Why it's wrong here

  Azure Traffic Manager resolves DNS queries and performs endpoint health checks to route end-user traffic to the closest or highest-priority endpoint, but it only controls client resolution of the service name. It does not replicate any underlying VM or disk data; if the primary region goes down, Traffic Manager can send users to a recovery region only if that region already has a running VM with current state. Any data written before the disaster would be lost unless a separate replication mechanism is in place, and DNS TTL plus probe intervals add delays measured in minutes—far too coarse for a strict RPO/RTO commitment.

• ✓

  Azure Site Recovery

  Why this is correct

  Azure Site Recovery orchestrates continuous, block-level replication of Azure VMs to a secondary region by using a mobility service extension that copies every write to a cache storage account and then to replicated managed disks. In Azure-to-Azure scenarios, this provides an RPO of 15–30 seconds, while crash-consistent and app-consistent snapshots are taken to balance performance and data loss. Recovery plans enable you to define failover sequences, execute runbooks or scripts, and update DNS or load balancer settings, which can compress RTO to minutes with predictable, testable outcomes. That coordination of replication state and application failover is exactly what makes Site Recovery the appropriate choice for a critical workload's DR solution.

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