Amazon Routing Policies

What Is Amazon Route 53?

Amazon Route 53 (Route 53) is a scalable and highly available Domain Name System (DNS) service. Released on December 5, 2010, it is part of Amazon.com's cloud computing platform, Amazon Web Services (AWS). The name is a possible reference to U.S. Routes, and "53" is a reference to the TCP/UDP port 53, where DNS server requests are addressed. In addition to being able to route users to various AWS services, including EC2 instances, Route 53 also enables AWS customers to route users to non-AWS infrastructure and to monitor the health of their application and its endpoints. Route 53's servers are distributed throughout the world. Amazon Route 53 supports full, end-to-end DNS resolution over IPv6. Recursive DNS resolvers on IPv6 networks can use either IPv4 or IPv6 transport to send DNS queries to Amazon Route 53.

What is Policy-Based Routing?

In computer networking, policy-based routing (PBR) is a technique used to make routing decisions based on policies set by the network administrator.

When a router receives a packet it normally decides where to forward it based on the destination address in the packet, which is then used to lookup an entry in a routing table. However, in some cases, there may be a need to forward the packet based on other criteria. For example, a network administrator might want to forward a packet based on the source address, not the destination address. This permits routing of packets originating from different sources to different networks even when the destinations are the same and can be useful when interconnecting several private networks.

Here is the full video based on AWS Routing policies👇👇

Routing policies are used to: 

• Manipulate route attributes (the attribute depends on the routing protocol) 
• Decide which routes go into the routing table 
• Decide which routes to advertise to neighbors 
• Redistribute routes

Route 53 Routing Policies

Simple

This is the default routing policy. Use this only when you have exactly one resource such as one EC2 web server. This policy can contain multiple values but it returns one resource. This policy is not recommended for production sites.

Weighted

This one is fantastic for new deployments or release testing new versions. It’s based on a numerical value ranging from 0 to 255. If you specify a value of 0 for all regions then it’s routed equally.

Failover

Allows creating two records for the same name. This starts like a simple policy but with a health check. If that single web server is unhealthy then you can point elsewhere. That next pointer can be another web server or possibly an error.html page hosted in AWS S3.

Geolocation

Use this when you want to serve your site based on the location of the client or user.

Geoproximity

This is somewhat complicated so I would like to point to original documentation for the full explanation.

Latency

When you have multiple resources in multiple regions, this policy routes the user, not to the closest resource necessarily but the resource that responds the fastest or lowest latency

Multivalue answer

This one lets your return multiple values for each of your resources. The client or user browser randomly chooses one. Optionally you can add health checks. If any value becomes unhealthy then the client chooses another value to resolve. This is not an alternative solution to load balancing, it’s an enhancement.

What is DNS TTL (Time To Live)?

What is time-to-live (TTL)?

Time-to-live (TTL) is a value for the period of time that a packet, or data, should exist on a computer or network before being discarded.

The meaning of TTL, or packet lifetime, depends on the context. For example, TTL is a value in an Internet Protocol (IP) packet that tells a network router when the packet has been in the network too long and should be discarded.

Here's the full video along with a hands-on demo that's based on TTL (time-to-live)👇👇

How Does TTL Work?

TTL's basic function revolves around managing information packets in relation to DNS requests. When one of these packets is created and transmitted through the internet, there is a chance that it will pass, continuously, from router to router forever. To prevent this from happening, each packet has a specific TTL or hop limit. It is also possible to examine the TTL log of a data packet to obtain information on how it has moved through the internet over the course of its travels.

Within each packet, there is a specified place where the TTL value is stored. This is a numerical value, and it indicates how much longer the packet should move around the internet. When a router receives a data packet, it takes away one unit from the TTL count before sending it on to the next destination within the network. This continues to happen until the TTL count within the packet drops all the way down to zero.

What is time-to-live in HTTP?

In Hypertext Transfer Protocol (HTTP), time-to-live describes the number of seconds it takes for cached web content to return before the webserver has to check again to ensure that the content is "fresh."

Settings on the webserver define a default value. Still, cache-control tags, which define the kinds of servers, if any, can cache the data, or expired tags, which represent a date and time when the content is stale, can override it in the HyperText Markup Language page headers.

What Are TTL Values?

When you set TTL values for your website, you choose a value in seconds. For example, a TTL value of 600 is the equivalent of 600 seconds or ten minutes.

The minimum available TTL is usually 30, equivalent to 30 seconds. You could theoretically set a TTL as low as one second. However, most sites use a default TTL of 3600 (one hour). The maximum TTL that you can apply is 86,400 (24 hours).

Technically, you can set any TTL value between the minimum and maximum parameters. Later in this article, we’ll discuss how you can choose the best time to live value for your site.

How Should You Choose a TTL?

Deciding on a suitable TTL for your needs can be challenging. Fortunately, there are some general guidelines that you can follow to see what fits your site best.

We recommend a TTL of 1-24 hours for most sites. Remember that TTL values are measured in seconds, so this is the equivalent of 3,600 to 86,400 seconds.

This TTL value can reduce loading time, which improves the user experience for your visitors and can decrease your bounce rate. The longer the better is a general rule, but remember to schedule any website maintenance accordingly.

How to create Records in AWS Route53

what is Route53?

Amazon Route 53 is a highly available and scalable Domain Name System (DNS) web service. You can use Route 53 to perform three main functions in any combination: domain registration, DNS routing, and health checking.

Amazon Route 53 pricing and billing

As with other AWS products, there are no contracts or minimum commitments for using Amazon Route 53. You pay only for the hosted zones that you configure and the number of DNS queries that Route 53 answers. For more information, see Amazon Route 53 Pricing  

For information about billing for AWS services, including how to view your bill and manage your account and payments, see the AWS Billing and Cost Management User Guide.

Here is the full video, based on AWS Route53 Domain configuration, Creating the first comment and Query those Records in AWS CloudShell👇👇

To create a record using the Route 53 console

1. Sign in to the AWS Management Console and open the Route 53 console at https://console.aws.amazon.com/route53/
   
   
   

   

   
   
   
   
   
   
2. Search for Route53 service
   
   
   
   
   
   
3. choose Hosted zones.
   
   

   
   
   
   
   
   
   
   
   
   
   
   
   
   
4. If you already have a hosted zone for your domain, skip to the next step. If you don't, select the "create a hosted zone" option and you can create it.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
5. Now If you are done with the Creating hosted zone, On the Hosted zones page, choose the name of the hosted zone that you want to create records in.
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
6. Choose Create Record.