The last work in the domain name represents the top-level domain name. The second-level comes after the top-level (i.e.
http://www.mywebsite.commight point to
http://m.yourwebsite.comthat is used when users browse to your domain from their mobile device. You might also want
mobile.yourwebsite.comto map to the same address.
Things to note:
What is a TTL? The length of time that a DNS record is cached on either the resolving server or the user's own local PC is equal to the value of the TTL in seconds. The lower to TTL, the faster changes to DNS records propagate throughout the internet.
The exam tips:
In the demo, a domain was registered through AWS and a few EC2 instances were stood up in different regions.
Simply, if we create an A Record with a naked domain name.
Simple routing was chosen with a TTL of 1 minute.
As for the value, both addresses were added on separate lines.
Essentially the Route53 would randomly select an address to be routed to.
If you specify multiple values in a record, Route 53 returns all values to the user in a random order.
Allows to split traffic based on different weights assigned.
As for the demo, a new health check was made for each of the EC2 instances.
When creating the A Records, you can specify a weight with a weight record policy. Ensure that the health check is also added here.
You'll create a separate record for each of the EC2 instances.
Used when you want to create an active/passive set up.
For example, you may want your primary site to be in EU-WEST-2 and secondary disaster recovery site in AP-SOUTHEAST-2.
When creating new records, select "failover".
It then asks you if it is
Secondary. The rest of the setup is as expected (also using health checks).
To demo the failover, the inbound security group was changed to disallow all inbound traffic so the primary would fail over to secondary.
Lets you choose here your traffic will be sent based on geographic location.
For example, you may want localization setup.
When creating the records, you can do it by continent or country.
Exam tip: if you need to route someone because of geographic requirement and not latency.
You can use Route 53 traffic flow to build a routing system that uses a combo:
From your users to your cloud or on-premises endpoints.
You can build it by scratch or using a template.
Geoproximity routing is only available with traffic flow.
Likely won't be on the exam. Just know that a bias expands or shrinks the size of the geographic region from which traffic is routed to a resource.
In the demo, this is done by creating a
traffic policy to build out the policies based on the GUI.
To use it, traffic flow must be enabled.
Allows you to route your traffic based on the lowest network latency for your end user (i.e. which region will give them the fastest response time).
To use it, you create a latency resouce record set for the EC2/ELB resource in each region that hosts your website. When Route 53 recieves a query or your site, it selects the latency resource record set for the region that gives the user the lowest latency.
The demo follows a similar routing policy flow as previous demoes but with the
Routing policy being set to
Latency with the region selecting.
The exam tips:
"Just Simple Routing with health checks".
As opposed to simple routing, this basically only returns the values for healthy resources. We also need to create a new record for each health check.