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Flashcards in Route53 Deck (10)
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1

DNS 101

  • ELB's do not have pre-defined IPv4 addresses, you resolve to them using a DNS name
  • Alias and CNAMES are similar in that you can map one DNS name (www.example.com) to another 'target' DNS name (elb1234.elb.amazonaws.com)
  • Key difference between Alias and CNAMES: A CNAME can't be used for naked domain names (zone apex). You can't have a CNAME for http://patin.com (but you can for http://www.patin.com), it must be either an A record or an Alias.
  • Given the choice, always choose an Alias record over a CNAME

DNS 101

  • ELB's do not have pre-defined IPv4 addresses, you resolve to them using a DNS name
  • Alias and CNAMES are similar in that you can map one DNS name (www.example.com) to another 'target' DNS name (elb1234.elb.amazonaws.com)
  • Key difference between Alias and CNAMES: A CNAME can't be used for naked domain names (zone apex). You can't have a CNAME for http://patin.com (but you can for http://www.patin.com), it must be either an A record or an Alias.

2

Alias Records

Alias resource record sets can save you time because Amazon Route 53 automatically recognizes changes in the record sets that the alias resource record set refers to.

For example, suppose an alias resource record set for example.com points to an ELB load balancer at lb1-1234.us-east-1.elb.amazonaws.com. If the IP address of the load balancer changes, Amazon Route 53 will automatically reflect those changes in DNS answers for example.com without any changes to the hosted zone that contains resource record sets for example.com

Alias Records

Alias resource record sets can save you time because Amazon Route 53 automatically recognizes changes in the record sets that the alias resource record set refers to.

For example, suppose an alias resource record set for example.com points to an ELB load balancer at lb1-1234.us-east-1.elb.amazonaws.com. If the IP address of the load balancer changes, Amazon Route 53 will automatically reflect those changes in DNS answers for example.com without any changes to the hosted zone that contains resource record sets for example.com

3

Route53 - Routing Policies

  • Simple
  • Weighted
  • Latency
  • Failover
  • Geolocation

Route53 - Routing Policies

  • Simple
  • Weighted
  • Latency
  • Failover
  • Geolocation

4

Routing Policies - Simple

This is the default routing policy when you create a new record set. This is most commonly used when you have a single resource that performs a given function for your domain, for example, one web server that serves content for the http://example.com

Routing Policies - Simple

This is the default routing policy when you create a new record set. This is most commonly used when you have a single resource that performs a given function for your domain, for example, one web server that serves content for the http://example.com

5

Routing Policies - Weighted

Weighted Routing Policies let you split your traffic based on different weights assigned.

For example you can set 10% of your traffic to go to US-EAST-1 and 90% to go to EU-WEST-1

 

Routing Policies - Weighted

Weighted Routing Policies let you split your traffic based on different weights assigned.

For example you can set 10% of your traffic to go to US-EAST-1 and 90% to go to EU-WEST-1

6

Routing Policies - Failover

Failover routing policies are used when you want to create an active/passive setup. For example you may want your primary site to be in EU-WEST-2 and your secondary DR site in AP-SOUTHEAST-2.

Route53 will monitor the health of your primary site using a healthcheck.

A healthcheck monitors the health of your end points.

Routing Policies - Failover

Failover routing policies are used when you want to create an active/passive setup. For example you may want your primary site to be in EU-WEST-2 and your secondary DR site in AP-SOUTHEAST-2.

Route53 will monitor the health of your primary site using a healthcheck.

A healthcheck monitors the health of your end points.

7

Routing Policies - Latency

Latency based routing 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 latency-based routing you create a latency resource record set for the Amazon EC2 (or ELB) resource in each region that hosts your website. When Amazon Route 53 receives a query for your site, it selects the latency resource record for the region that gives the user the lowest latency. Route53 then responds with the value associated with that resource record set. 

 

Routing Policies - Latency

Latency based routing 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 latency-based routing you create a latency resource record set for the Amazon EC2 (or ELB) resource in each region that hosts your website. When Amazon Route 53 receives a query for your site, it selects the latency resource record for the region that gives the user the lowest latency. Route53 then responds with the value associated with that resource record set. 

8

Compare Elastic Load Balancing and Amazon Route 53

Compare Elastic Load Balancing and Amazon Route 53

9

Routing Policies - Geolocation

Geolocation routing lets you choose where your traffic will be sent based on the geographic location of your users (i.e. the location from which DNS queries originate).

For example, you might want all queries from Europe to be routed to a fleet of EC2 instances that are specifically configured for your European customers. These servers may have the local language of your European customers and all prices are displayed in Euros.

Routing Policies - Geolocation

Geolocation routing lets you choose where your traffic will be sent based on the geographic location of your users (i.e. the location from which DNS queries originate).

For example, you might want all queries from Europe to be routed to a fleet of EC2 instances that are specifically configured for your European customers. These servers may have the local language of your European customers and all prices are displayed in Euros.

10

What kinds of Records does Amazon Route 53 support?

  • Many standard DNS records are supported
  • Alias records provide an Amazon Route 53-specific extension to DNS functionality. Instead of an IP address or domain name:
    • Amazon CloudFront distribution
    • Elastic Load Balacing load balancer
    • Amazon S3 bucket configured as a static website
    • Amazon Route 53 resource record set in the same hosted zone

What kinds of Records does Amazon Route 53 support?

  • Many standard DNS records are supported
  • Alias records provide an Amazon Route 53-specific extension to DNS functionality. Instead of an IP address or domain name:
    • Amazon CloudFront distribution
    • Elastic Load Balacing load balancer
    • Amazon S3 bucket configured as a static website
    • Amazon Route 53 resource record set in the same hosted zone