If you’re not aware of Amazon Route 53, I’d suggest you to read What is Amazon Route 53? before going through the FAQ.

  • DNS is a globally distributed service that translates human readable names like www.example.com into the numeric IP addresses like 192.0.2.1 that computers use to connect to each other.

  • With Amazon Route 53, you can create and manage your public DNS records.

  • To provide you with a highly available service, each Amazon Route 53 hosted zone is served by its own set of virtual DNS servers. The DNS server names for each hosted zone are thus assigned by the system when that hosted zone is created.

  • Anycast is a networking and routing technology that helps your end users’ DNS queries get answered from the optimal Route 53 location given network conditions. As a result, your users get high availability and improved performance with Route 53.

  • Route 53 supports importing standard DNS zone files which can be exported from many DNS providers as well as standard DNS server software such as BIND.

  • A transactional change helps ensure that the change is consistent, reliable, and independent of other changes. Amazon Route 53 has been designed so that changes complete entirely on any individual DNS server, or not at all.

  • Associating multiple IP addresses with a single record is often used for balancing the load of geographically-distributed web servers. Amazon Route 53 allows you to list multiple IP addresses for an A record and responds to DNS requests with the list of all configured IP addresses.

  • Amazon Route 53 offers a special type of record called an ‘Alias’ record that lets you map your zone apex (example.com) DNS name to the DNS name for your ELB load balancer, S3, CloudFront, ELB, VPC Endpoint (such as my-loadbalancer-1234567890.us-west-2.elb.amazonaws.com). IP addresses associated with load balancers can change at any time due to scaling up, scaling down, or software updates. Route 53 responds to each request for an Alias record with one or more IP addresses for the load balancer. Route 53 supports alias records for three types of load balancers: Application Load Balancers, Network Load Balancers, and Classic Load Balancers.

  • Weighted Round Robin allows you to assign weights to resource record sets in order to specify the frequency with which different responses are served.

  • Route 53 Geo DNS lets you balance load by directing requests to specific endpoints based on the geographic location from which the request originates. Geo DNS makes it possible to customize localized content, such as presenting detail pages in the right language or restricting distribution of content to only the markets you have licensed.

  • Yes, we strongly recommend that you configure a global record, to ensure that Route 53 can provide a response to DNS queries from all possible locations—even if you have created specific records for each continent, country, or state where you expect your end users will be located. Route 53 will return the value contained in your global record in the following cases:

    • The DNS query comes from an IP address not recognized by Route 53’s Geo IP database.

    • The DNS query comes from a location not included in any of the specific Geo DNS records you have created.

  • Yes, you can have Geo DNS records for overlapping geographic regions (e.g., a continent and countries within that continent, or a country and states within that country). For each end user’s location, Route 53 will return the most specific Geo DNS record that includes that location. In other words, for a given end user’s location, Route 53 will first return a state record; if no state record is found, Route 53 will return a country record; if no country record is found, Route 53 will return a continent record; and finally, if no continent record is found, Route 53 will return the global record.

  • Route 53 now supports multivalue answers in response to DNS queries. While not a substitute for a load balancer, the ability to return multiple health-checkable IP addresses in response to DNS queries is a way to use DNS to improve availability and load balancing. If you want to route traffic randomly to multiple resources, such as web servers, you can create one multivalue answer record for each resource and, optionally, associate an Amazon Route 53 health check with each record. Amazon Route 53 supports up to eight healthy records in response to each DNS query.

  • Amazon Route 53 Traffic Flow makes it easy for developers to create policies that route traffic based on the constraints they care most about, including latency, endpoint health, load, geoproximity and geography.

  • A traffic policy is the set of rules that you define to route end users’ requests to one of your application’s endpoints. By itself, a traffic policy doesn’t affect how end users are routed to your application because it isn’t yet associated with your application’s DNS name (such as www.example.com). To start using Amazon Route 53 Traffic Flow to route traffic to your application using the traffic policy you’ve created, you create a policy record which associates the traffic policy with the appropriate DNS name within an Amazon Route 53 hosted zone that you own.

  • You can reuse a policy to manage more than one DNS name in one of two ways. First, you can create additional policy records using the policy. Note that there is an additional charge for using this method because you are billed for each policy record that you create. The second method is to create one policy record using the policy, and then for each additional DNS name that you want to manage using the policy, you create a standard CNAME record pointing at the DNS name of the policy record that you created.

  • Changing the geoproximity bias value on an endpoint either expands or shrinks the area from which Route 53 routes traffic to a resource. The geoproximity bias can’t accurately predict the load factor, though, because a small shift in the size of geographic areas might include or exclude major metropolitan areas that generate large numbers of queries. As of today, bias can only be applied to geoproximity rules.

  • Private DNS is a Route 53 feature that lets you have authoritative DNS within your VPCs without exposing your DNS records (including the name of the resource and its IP address(es) to the Internet.

  • Route 53 Private DNS uses VPC to manage visibility and provide DNS resolution for private DNS hosted zones. To take advantage of Route 53 Private DNS, you must configure a VPC and migrate your resources into it.

  • Yes, you can associate multiple VPCs with a single hosted zone.

  • Yes, you can associate VPCs belonging to different accounts with a single hosted zone.

  • Yes, you can block domains and specific DNS names by creating these names in one or more Private DNS hosted zones and pointing these names to your own server (or another location that you manage).

  • DNS Failover consists of two components: health checks and failover. Health checks are automated requests sent over the Internet to your application to verify that your application is reachable, available, and functional. You can configure the health checks to be similar to the typical requests made by your users, such as requesting a web page from a specific URL. With DNS failover, Route 53 only returns answers for resources that are healthy and reachable from the outside world, so that your end users are routed away from a failed or unhealthy part of your application.

  • Yes, you can configure DNS Failover for Elastic Load Balancers (ELBs). To enable DNS Failover for an ELB endpoint, create an Alias record pointing to the ELB and set the “Evaluate Target Health” parameter to true.

  • No, Route 53 does not make routing decisions based on the load or available traffic capacity of your endpoints. You will need to ensure that you have available capacity at your other endpoints, or the ability to scale at those endpoints, in order to handle the traffic that had been flowing to your failed endpoint.

  • No. Route 53 health checks consider an HTTP 3xx code to be a successful response, so they don’t follow the redirect.

  • You can get metrics on the health of your load balancer in two ways. First, Elastic Load Balancing publishes metrics that indicate the health of the load balancer and the number of healthy instances behind it. Use CloudWatch for this. Second, you can create your own health check against the CNAME provided by the ELB, e.g. elb-example-123456678.us-west-2.elb.amazonaws.com. You won’t use this health check for DNS Failover itself (because the “Evaluate Target Health” option provides DNS Failover for you), but you can view the CloudWatch metrics for this health check and create alarms to be notified if the health check fails.

  • If you specify a domain name as the endpoint of an Amazon Route 53 health check, Amazon Route 53 will look up the IPv4 address of that domain name and will connect to the endpoint using IPv4. Amazon Route 53 will not attempt to look up the IPv6 address for an endpoint that is specified by domain name. If you want to perform a health check over IPv6 instead of IPv4, select “IP address” instead of “domain name” as your endpoint type, and enter the IPv6 address in the “IP address” field.

  • Amazon is a reseller of the registrar Gandi. As the registrar of record, Gandi is required by ICANN to contact the registrant to verify their contact information at the time of initial registration.

  • First, you need to get a list of the DNS record data for your domain name, generally available in the form of a “zone file” that you can get from your existing DNS provider. With the DNS record data in hand, you can use Route 53’s Management Console or simple web-services interface to create a hosted zone that can store the DNS records for your domain name and follow its transfer process, which will include such steps as updating the name servers for your domain name to the ones associated with your hosted zone. To complete the domain name transfer process, contact the registrar with whom you registered your domain name and follow its transfer process, which will include steps such as updating the name servers for your domain name to the ones associated with your hosted zone. As soon as your registrar propagates the new name server delegations, the DNS queries from your end users will start to get answered by the Route 53 DNS servers.

  • Route 53 Resolver is a regional DNS service that provides recursive DNS lookups for names hosted in EC2 as well as public names on the internet. This functionality is available by default in every Amazon Virtual Private Cloud (VPC). For hybrid cloud scenarios you can configure conditional forwarding rules and DNS endpoints to enable DNS resolution across AWS Direct Connect and AWS Managed VPN.

  • Amazon Route 53 is both an Authoritative DNS service and Recursive DNS service. Authoritative DNS contains the final answer to a DNS query, generally an IP address. Clients (such as mobile devices, applications running in the cloud, or servers in your datacenter) don’t actually talk directly to authoritative DNS services, except in very rare cases. Instead, clients talk to recursive DNS services (also known as DNS resolvers) which find the correct authoritative answer for any DNS query. Route 53 Resolver is a recursive DNS service.

  • A DNS endpoint includes one or more elastic network interfaces (ENI) that attach to your Amazon Virtual Private Cloud (VPC). Each ENI is assigned an IP address from the subnet space of the VPC where it is located. This IP address can then serve as a forwarding target for on-premises DNS servers to forward queries. Endpoints are required both for DNS query traffic that you’re forwarding from VPCs to your network and from your network to your VPCs over AWS Direct Connect and Managed VPN.

  • Route 53 Resolver is integrated with AWS Resource Access Manager (RAM) which provides customers with a simple way to share their resources across AWS accounts or within their AWS Organization. Rules can be created in one primary account and then shared across multiple accounts using RAM. Once shared, the rules still need to be applied to VPCs in those accounts before they can take effect.

  • Amazon Route 53 public and private DNS, traffic flow, health checks, and domain name registration are all global services.

Reference: Amazon Route 53 FAQs