Lab 3C — Route 53 advanced routing

15 timed scenario questions (~24 min, ~96 sec each). Reinforces night-25-route53-routing.md and night-25-lab-route53-setup scripts. Answer without peeking at night-25-quiz-answers.json first.

1. 1.witcoskitech.com uses a single A alias to CloudFront with no routing policy. A stakeholder asks for 10% of DNS answers to hit a canary CloudFront distribution before full cutover. Which Route 53 policy fits?

   A.Weighted routing — two records with SetId values and weights 90 and 10B.Failover routing — PRIMARY and SECONDARY without attaching a health checkC.Simple routing — add a second A record that shares the same DNS nameD.Geolocation routing — send roughly 10% of countries toward the canary

2. 2.GSA prod designs DR: primary ALB in us-east-1 serves api.globalskiatlas.com; secondary is an S3 static maintenance site in us-west-2. Route 53 must stop sending users to the primary when the app is down. Minimum DNS configuration?

   A.Latency records in both Regions — Route 53 fails over when latency spikesB.Failover PRIMARY alias to ALB with a health check; SECONDARY to S3 without oneC.Weighted 50/50 between ALB and S3 — health inferred automatically from HTTP 503D.Multivalue answer returning both ALB and S3 endpoints in every DNS response

3. 3.You deploy identical API stacks in us-east-1 and eu-west-1. Users worldwide should hit the lowest-latency Region. Which Route 53 policy?

   A.Weighted routing with equal weights — latency selection happens automaticallyB.Geolocation routing with a single Country=* default record for all clientsC.Latency routing — one latency record per Region pointing at each endpointD.Simple routing — Route 53 measures all Regions and always picks the fastest

4. 4.night-25-lab creates night25-failover.witcoskitech.com. PRIMARY aliases CloudFront with an HTTPS health check; SECONDARY aliases www. The health check shows Unhealthy for 5 minutes but clients still resolve PRIMARY. Likely cause?

   A.SECONDARY record also needs the same health check ID attached to fail overB.Failover requires NLB — CloudFront aliases cannot participate in health checksC.Health checks only work when the hosted zone is private and VPC-associatedD.Clients or recursive resolvers cache the prior DNS answer until TTL expires

5. 5.EU privacy rules require EU visitors to resolve to an eu-west-1 CloudFront distribution; everyone else uses us-east-1. Which policy?

   A.Geolocation routing — Continent or Country records for EU plus a defaultB.Latency routing — EU is always assumed the lowest-latency choice for EU usersC.Weighted routing — set EU weight to 100 and US weight to zero for all clientsD.Failover routing — EU is PRIMARY and US remains the passive SECONDARY endpoint

6. 6.Exam scenario: apex domain example.com must point at a CloudFront distribution. Why is an A/AAAA alias preferred over a CNAME at the zone apex?

   A.CloudFront only accepts CNAME targets and rejects alias records entirelyB.CNAME records are not permitted at the zone apex per DNS standardsC.Alias records require a longer TTL than CNAME — better caching at apexD.CNAME at apex is allowed but costs more per query than an alias record

7. 7.An ALB in us-east-1 spans three AZs. One AZ loses power; targets in other AZs stay healthy. Clients use the ALB DNS name directly (no Route 53 routing policy). What happens?

   A.All traffic fails until Route 53 failover flips clients over to a secondaryB.Route 53 automatically creates weighted records for each surviving AZ nodeC.New connections reach healthy ALB nodes in remaining AZs — ALB is multi-AZD.Clients must manually switch to the NLB DNS name to restore full connectivity

8. 8.A public website behind CloudFront must fail over to a static S3 maintenance origin when the primary custom origin returns 5xx. You want edge-level origin failover without changing DNS. Which approach?

   A.Route 53 geolocation records that switch origins whenever HTTP status is 5xxB.API Gateway stage cache that serves a maintenance page after origin timeoutsC.Weighted Route 53 records that shift 100% of traffic after a short 60s TTLD.CloudFront origin group with primary/secondary origins and failover status codes

9. 9.Route 53 health check on https://witcoskitech.com/HTML/index.html reports Healthy while the ALB behind a separate api.example.com returns 502. Why can both be true?

   A.One health check monitors the static site; ALB target health is separateB.Route 53 health checks always mirror ALB target-group health automaticallyC.HTTPS health checks cannot run against CloudFront distributions at allD.Health checks only apply to failover SECONDARY records, never PRIMARY

10. 10.You want Route 53 to return up to eight healthy A record IPs so clients pick one at random. No Application Load Balancer in the design. Which policy?

    A.Weighted routing with eight equal weights on the same DNS nameB.Multivalue answer routing with health checks on each IP recordC.Latency routing with eight Regions registered in a single accountD.Geoproximity routing with bias set to zero in every AWS Region

11. 11.You need active-active multi-Region API endpoints so healthy Regions keep receiving traffic, and unhealthy ones are removed from DNS answers. Which Route 53 design fits best?

    A.Simple routing with one A record that lists every Regional ALB IP in the answerB.Failover PRIMARY/SECONDARY only — secondary stays completely idle until primary failsC.Latency or weighted records with health checks so unhealthy endpoints are skippedD.Private hosted zone associated to every VPC — public internet clients resolve internally

12. 12.GSA compares Route 53 latency routing vs AWS Global Accelerator for worldwide API traffic. Best differentiator for the exam?

    A.Route 53 latency works only with CloudFront; Global Accelerator only with ALBB.Global Accelerator cannot health-check endpoints at all; Route 53 always canC.Latency routing requires health checks; Global Accelerator never evaluates healthD.Global Accelerator uses static anycast IPs and edge steering; Route 53 is DNS-level

13. 13.Hybrid exam: on-prem servers must resolve internal-only hostnames like db.corp.local inside the VPC while public users resolve globalskiatlas.com on the internet. Which Route 53 feature for internal names?

    A.Private hosted zone associated with the VPC for internal DNS namesB.Public hosted zone with geolocation routing for corp.local recordsC.Latency routing on the apex domain to prefer on-premises resolversD.CloudFront alternate domain name registered for db.corp.local hosts

14. 14.Failover PRIMARY points to an ALB alias. Operators want Route 53 to fail over when any single unhealthy target remains behind the ALB. What is the exam-accurate approach?

    A.Set ALB health-check interval to 1 second — Route 53 inherits it automaticallyB.Use calculated/child health checks that evaluate ALB target health conditionsC.Use weighted routing — unhealthy targets automatically receive weight zeroD.Attach the health check only to the SECONDARY record, never PRIMARY

15. 15.night-25-lab uses night25-simple.witcoskitech.com with simple routing (one alias). Production apex witcoskitech.com uses the same pattern. What changes when you add weighted records on a different subdomain?

    A.Simple routing on the apex is replaced by weighted policy at the whole zone levelB.CloudFront requires a new distribution for each routing policy type that you addC.Nothing on apex — routing policy is per record name; subdomains stay independentD.Health checks become mandatory for every record set defined in that hosted zone