Route 53 Flashcards
You are setting up a web application and want to use Amazon Route 53 to distribute incoming traffic to two different EC2 instances located in separate regions. Which routing policy should you use to serve traffic based on the geographic location of your users?
A) Weighted Routing
B) Simple Routing
C) Latency-Based Routing
D) Geolocation Routing
D
Amazon Route 53’s Geolocation Routing lets you route traffic based on the geographic location of your users, which means the location from which DNS queries originate. This can be particularly useful when you want to deliver content to users from servers that are closest to them, or when you have content restrictions based on geographic locations.
A) Weighted Routing allows you to route traffic to different resources in specified proportions (e.g., 80% to Resource A and 20% to Resource B).
B) Simple Routing is for routing internet traffic to a single resource.
C) Latency-Based Routing routes traffic based on the lowest network latency for your end user (i.e., to the AWS region that provides the fastest response time).
Your company wants to set up a failover mechanism using Route 53 to redirect traffic from a primary site to a secondary site in case the primary site becomes unavailable. Which Route 53 routing policy should you use to accomplish this?
A) Weighted Routing
B) Failover Routing
C) Multi-value Answer Routing
D) Geolocation Routing
B
Failover Routing in Amazon Route 53 allows you to route traffic to a backup resource when your primary resource is unhealthy or unavailable. In a failover configuration, you create two resource record sets: a primary and a secondary (or backup). Route 53 will direct traffic to the backup resource when health checks indicate that the primary resource is unavailable.
C) Multi-value Answer Routing allows you to respond to DNS queries with up to eight healthy records selected at random, which can be useful for balancing loads and ensuring availability, but it does not provide a primary-secondary failover mechanism.
You have registered a domain using Amazon Route 53. After setting up a record for your website, you notice that the DNS changes have not propagated after a couple of hours. Which of the following could be reasons for the delay?
A) The Time to Live (TTL) value set for the record is too high.
B) Route 53 does not support immediate propagation.
C) You didn’t set up a SOA (Start of Authority) record.
D) The VPC security group is blocking DNS requests.
A
The Time to Live (TTL) value determines how long a DNS resolver should cache the DNS query results. If you’ve set a high TTL, then the DNS resolver will continue to use its cached value until that TTL expires. Therefore, if you make a change to a DNS record but the TTL has not yet expired for resolvers that have cached the previous value, those resolvers will continue to return the old value until the TTL expires.
B) Route 53 does support immediate propagation. However, due to caching by DNS resolvers (controlled by TTL), changes can take time to be seen globally.
C) While an SOA (Start of Authority) record is important in DNS setups, not having one doesn’t necessarily prevent propagation of other records. It provides administrative information about the DNS zone.
D) VPC security groups control inbound and outbound traffic for resources within a VPC. They wouldn’t be the primary reason for DNS propagation delays.
You are setting up a health check in Amazon Route 53 for your application. Which of the following is NOT a valid health check endpoint target in Route 53?
A) An Elastic Load Balancer (ELB) endpoint.
B) A specific IP address and port.
C) An EC2 instance based on its instance ID.
D) An Amazon S3 static website.
C
When you use Amazon Route 53 Traffic Flow to create complex routing configurations, which visual editor component represents a DNS record and its settings?
A) Endpoint
B) Policy Record
C) Traffic Policy
D) Rule Action
B
In Amazon Route 53 Traffic Flow, a Policy Record represents a DNS record and its associated configurations.
A brief overview of the options:
A) Endpoint represents the final target of the traffic (e.g., an IP address, an ELB, etc.).
B) Policy Record is the representation of the DNS record in a visual editor.
C) Traffic Policy is a document that specifies how to route traffic based on various criteria, such as health checks, geographic location, and more.
D) Rule Action defines what happens when a particular rule’s conditions are met.
In Amazon Route 53, which type of record is used to implement SSL/TLS security on a domain without needing to route traffic through a separate SSL negotiation?
A) MX Record
B) TXT Record
C) A Record
D) CAA Record
D
A CAA (Certification Authority Authorization) record is a DNS record type that allows domain owners to specify which certificate authorities (CAs) are permitted to issue certificates for their domain. This helps improve domain security by preventing unauthorized issuance of certificates for your domain. While the CAA record itself doesn’t implement SSL/TLS, it plays a crucial role in the SSL/TLS certificate management process.
Brief overview of the other options:
A) MX Record is used to route email messages to a mail server for a domain.
B) TXT Record is used to hold text information for a domain. It can be used for various purposes like verifying domain ownership.
C) A Record maps a domain name to an IPv4 address.
When using Amazon Route 53 Resolver, what does a “Resolver Rule” define?
A) The forwarding rule for a specific domain.
B) The health check parameters for DNS endpoints.
C) The TTL values for all domain records.
D) The geolocation regions for traffic routing.
A
In Amazon Route 53 Resolver, a “Resolver Rule” specifies the domain names for which DNS queries are forwarded. You can configure rules to forward queries to different target IP endpoints based on the domain name in the query. It’s especially useful when connecting on-premises data centers with AWS using hybrid cloud architectures.
In Amazon Route 53, which DNS record type is primarily used to link a domain name or subdomain to an IPv6 address?
A) A Record
B) MX Record
C) AAAA Record
D) CNAME Record
C
An AAAA Record, commonly referred to as a “quad-A record”, maps a domain or subdomain to an IPv6 address. It serves a similar function to an A Record, but for IPv6 addresses instead of IPv4.
A brief overview of the other options:
A) A Record maps a domain or subdomain to an IPv4 address.
B) MX Record is used to route email messages to a mail server for a domain.
D) CNAME Record creates an alias from one domain name to another domain name.
When creating a health check in Amazon Route 53, what does the “Request Interval” represent?
A) The amount of time Route 53 waits after receiving a response before it sends the next health-check request.
B) The duration for which Route 53 considers the endpoint healthy after a successful health check.
C) The time it takes for a health check to be marked as ‘Unhealthy’ after consecutive failed attempts.
D) The time period for which the health check metrics are stored.
A
Which of the following best describes the Simple Routing Policy in Amazon Route 53?
A) Directs traffic to multiple resources in a proportion that you define.
B) Routes traffic to a primary resource unless it’s unhealthy, then to a secondary resource.
C) Directs traffic based on the geographic location of your users.
D) Routes traffic to a single resource that you specify.
D
The Simple Routing Policy in Amazon Route 53 is used for basic routing where all the traffic for a domain or subdomain is directed to a single resource, such as a web server or an Elastic Load Balancer.
A brief overview of the other options:
A) Weighted Routing directs traffic to multiple resources in proportions that you define.
B) Failover Routing routes traffic to a primary resource and switches to a secondary resource when the primary is unhealthy.
C) Geolocation Routing routes traffic based on the geographic location of your users.
In the context of Amazon Route 53, what is the primary purpose of a “Reusable Delegation Set”?
A) To enable domain name transfer between AWS accounts.
B) To specify which certificate authorities (CAs) are allowed to issue certificates for your domain.
C) To use the same set of four name servers across multiple hosted zones.
D) To configure a group of health checks and apply them to multiple resources.
C
A “Reusable Delegation Set” in Amazon Route 53 allows you to use the same set of four authoritative name servers across multiple hosted zones. This can be especially useful for organizations that have many domains and prefer to use a consistent set of name servers for easier management.
Which of the following is true regarding the relationship between Amazon Route 53 and AWS CloudFront distributions?
A) Route 53 can only route traffic to CloudFront distributions if they are in the same AWS region.
B) Route 53 automatically encrypts traffic between itself and CloudFront distributions using AWS Key Management Service (KMS).
C) Route 53 can create alias records that point to CloudFront distributions, allowing you to route traffic without incurring DNS query charges.
D) Route 53 requires a special IAM policy to be able to route traffic to CloudFront distributions.
C
Amazon Route 53 provides a unique feature called “alias records” that lets you point your domain to certain AWS resources, such as CloudFront distributions, Elastic Load Balancers, or S3 buckets configured as websites. When you use an alias record to point to an AWS resource, you don’t incur the usual DNS query charges that come with a typical CNAME record.
You have purchased mycoolcompany.com on Amazon Route 53 Registrar and would like the domain to point to your Elastic Load Balancer my-elb-1234567890.us-west-2.elb.amazonaws.com. Which Route 53 Record type must you use here?
A) CNAME
B) Alias
B
You can’t create a CNAME record that has the same name as the top node of the DNS namespace (Zone Apex), in our case “mycoolcompany.com.”
You have deployed a new Elastic Beanstalk environment and would like to direct 5% of your production traffic to this new environment. This allows you to monitor for CloudWatch metrics and ensuring that there’re no bugs exist with your new environment. Which Route 53 Record type allows you to do so?
A) Simple
B) Weighted
C) Latency
D) Failover
B
Weighted Routing Policy allows you to redirect part of the traffic based on weight (e.g., percentage). It’s a common use case to send part of traffic to a new version of your application.
You have updated a Route 53 Record’s myapp.mydomain.com value to point to a new Elastic Load Balancer, but it looks like users are still redirected to the old ELB. What is a possible cause for this behavior?
A) Because of the Alias record
B) Because of the CNAME record
C) Because of the TTL
D) Because of Route 53 Health Checks
C)
Each DNS record has a TTL (Time To Live) which orders clients for how long to cache these values and not overload the DNS Resolver with DNS requests. The TTL value should be set to strike a balance between how long the value should be cached vs. how many requests should go to the DNS Resolver.
