- [Narrator] Okay, cloud academy ninjas, let's review Route 53 for our exam preparation. Domain names are registered with domain registrars that in turn, register the domain names with InterNIC, and that's a service of ICANN. So, ICANN has 30 nor so route service globally, which direct DNS requests to the current authority for the relevant top-level domain or TLD. Now, ICANN enforces uniqueness of domain names across the internet. And each domain name becomes registered in a central data base known as the WhoIS database. You probably seen that a few times, WhoIS is basically the source of truth. So domains are defined by their top-level domains or TLD's, and TLD's are controlled by IANA, which is basically a route zone database. Now Amazon Route 53 enables you to register a top-level domain or a TLD. The benefit of using Route 53 to register your domains, is your domain records will be managed from one place. So Route 53 organizes your DNS records into hosted zones. And a hosted zone stores ANAME records for your domain. Now these records consist of any of the DNS supported domain extensions. And the most common ones are the ANAME record, the CNAME record, the MX record, and any other supported record types. Now Route 53 supports five routing policies. So the first and most amazing one is failover, and that's basically a crucial component for a disaster recovery service. Because you can route your traffic from your resources in a primary location to a standby location. Another routing policy is just a simple routing policy, which is most commonly used when you have a single resource that performs a given function for your domain, e.g. And then we have latency-based routing, which is useful if you need to route your traffic based on the lowest latency, i.e., it's the shortest response time to where you make your request from. So if I'm requesting a service from a outer location, latency-based routing means that I will be delivered a response based on the quickest response time. So, it gets users your fastest load times of any page asset. The other routing type is geolocation, and that's used to route your traffic based on the end user's location, so whereabouts your based. The geolocation will suffice for the majority of used cases, if you want to get the fastest, most efficient response times; however, if you do have security or governance compliance requirements, say for example, a user in the U.S. must view a specific server, located in a specific zone, i.e., the U.S., then you may need to add a third party service to accurately determine the origin location of the requester's IP address. And the final routing policy is weighted. Now you can use this if you want to route a percentage of your traffic to one particular resource or resources. Say, if you want to create a group of weighted resources record sets, you create two or more resource record sets that have the same DNS name and type, and then you assign each resource record a unique identify and a relative weight. So that means that you can direct 60% of your traffic to one server and 40% of your traffic to another. Now you should route your traffic based on where your end users are located. And the best default routing policy to achieve this is geolocation routing. Now a few common domain name gotchas, first off, AAAA record is used to route traffic to an IPv6 address, so an ANAME record is used for IPv4 adresses, but if you also want to add IPv6 support, you have to have an AAAA record. Just remember that. When you register your domain name with a domain registrar, they then register your domain name with InterNIC, All right, so, if you get a question about where do you register your domain name, you register it with a domain registrar. Now, geolocation is generally the best routing policy, if you wanna route traffic to where your end user is located. And remember, a PTR record, PTR record, is used for reverse DNS, right? So if you wanna resolve an IP address to a domain name, so a reverse lookup, PTR record. Okay, good stuff, let's get on to the next domain.