SOA-C02 Networking and Content Delivery 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.

• ✗

  The primary record is not an alias record

  Why it's wrong here

  Alias records in Route 53 are only required when you want to route traffic to AWS resources like Elastic Load Balancers or CloudFront distributions without paying for queries, but failover routing works equally with standard A or AAAA records. In a failover configuration, the routing decision is based on the health check associated with the record, not on whether the record is an alias. The lack of an alias record would not prevent Route 53 from evaluating the health status and switching to the secondary record, so this is not the cause of the problem.

• ✗

  The domain registrar's nameservers are not pointing to Route 53

  Why it's wrong here

  For the domain to resolve at all, the registrar's nameservers must delegate the zone to the Route 53 hosted zone's nameservers; if they are not pointing correctly, end users would get NXDOMAIN or a different answer, and Route 53 would never receive queries for the record. Since the symptom is that failover does not occur rather than that the domain is entirely unresolvable, DNS resolution is already working, so delegation is not the issue. Nameserver delegation affects query routing, not Route 53's ability to monitor health checks or execute failover.

• ✓

  The health check is configured to monitor the secondary endpoint instead of the primary

  Why this is correct

  In Route 53 failover routing, the primary record must be associated with a health check that monitors the primary endpoint. If the health check instead monitors the secondary endpoint, it will remain healthy even when the primary goes down, so Route 53 will never see the failure and will continue returning the primary record in responses. This configuration directly prevents failover from triggering, making it the correct explanation for why the secondary resource is never used.

• ✗

  The TTL on the primary record is set too high

  Why it's wrong here

  The TTL determines how long recursive resolvers and clients cache DNS responses; it does not influence Route 53's server-side decision to switch records when a health check fails. If the TTL were too high, you might observe that some clients continue using the old primary IP for a while after failover occurs, but you would still expect Route 53 to eventually respond with the secondary. In a scenario where failover never happens, the faulty logic lies in the health check configuration, not in the TTL value.

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