Route 53 Flashcards
What is the Record Type for Route 53?
A - Maps a hostname to IPV4
AAAA - Maps a hostname to IPV6
CNAME - Maps a hostname to another hostname
- The Target is a domain name that must have an A or AAAA record
NS - Name Servers for the Hosted Zone
how many hosted zones are there in Route 53?
There are two hosted zones:
public hosted zones- contains a record that is specified how to route traffic on the Internet (public domain names)
private hosted zones - contained records that specify how you route traffic within one or more PVC (private domain names)
Difference between CNAME vs Alias
CNAME point a hostname to another hostname e.g. app.mydomain.com > blabla.anything.com. Cname only works for non-root domain i.e. something.mydomain.com. But it will not work for mydomain.com
Alias:
- points a hostname to an AWS resource e.g. app.mydomain.com => blabla.amazonaws.com
- It works for both root and non-root domain.
- It’s free or
- Native health check
- You cannot set TTL (time to live) in the Alias
- You cannot set an alias record for an EC2 DNS name.
The exam may have a question on this.
what is routing policies – simple?
It routes traffic to a single resource.
It is possible to specify multiple values in the same record. If multiple values are returned, the client can choose a random one.
When an alias is enabled, you can specify only one AWS resource.
What is the weighted routing policy?
In the weighted routing policy, you can specify a weight to each resource to which you want traffic to be routed. The DNS records must have the same name and type. It can be associated with health checks. The use cases could be load balancing between regions, testing new application versions, etc.
Assign a weight of zero to a record to stop sending traffic to a resource.
What is latency based routing policies?
Redirect to the resource that has the least latency. Super helpful when latency for users is a priority. Let’s see is based on traffic between users and AWS regions. For example, German users may be directed to the US if the latency is low on the US server. It can be associated with help checks, and it has failover capabilities.
What are Route 53 health checks?
Amazon Route 53 health checks monitor the health and performance of your web applications, web servers, and other resources. Each health check that you create can monitor one of the following:
The health of a specified resource, such as a web server.
The status of other health checks.
The status of an Amazon CloudWatch alarm.
Additionally, with Amazon Route 53 Application Recovery Controller, you can set up routing control health checks with DNS failover records to manage traffic failover for your application.
what is Route 53 – Calculated Health check?
You can now combine the results of multiple Route 53 health checks into a single value using Boolean operations (AND, OR, and NOT). This allows you to create a single health check that combines the results of other checks in a useful way.
How health check can be performed for privately hosted zones in Route 53?
Route 53 health checks are outside the VPC, they cannot access the private endpoint. You can create cloud watch metrics, and associate a cloud watch alarm, and then create a health check that checks the alarm itself.
What is Route 53 policy for Failover?
Failover routing lets you route traffic to a resource when the resource is healthy and to a different resource when the first resource is unhealthy. The primary and secondary records can route traffic to anything from an Amazon S3 bucket that is configured as a website to a complex tree of records.
What is Route 53 Geolocation policy?
Geolocation routing lets you choose the resources that serve your traffic based on the geographic location of your users, meaning the location where DNS queries originate from. For example, you might want all queries from Europe to be routed to an ELB load balancer in the Frankfurt region.
What is Route 53 Geopoximity policy?
Geoproximity routing lets Amazon Route 53 route traffic to your resources based on the geographic location of your users and your resources. You can also optionally choose to route more traffic or less to a given resource by specifying a value, known as a bias. A bias expands or shrinks the size of the geographic region from which traffic is routed to a resource.
What is Multi-value routing policies?
Multivalue answer routing lets you configure Amazon Route 53 to return multiple values, such as IP addresses for your web servers, in response to DNS queries. You can specify multiple values for almost any record, but multivalue answer routing also lets you check the health of each resource, so Route 53 returns only values for healthy resources.
