AWS ::: Devloper ::: Section 9: Route 53

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85. What is a DNS?

 All of these are going to be your Hierarchy of your domain names. 

 There is going to be a Domain Registrar - This is where you will register your domain name.

• Amazon Route 53 
• GoDaddy

 Or any other domain registrar you can find on line. Then you have DNS record and you have different

 

The last . dot is the root of all the domain names .

1.  .com :  is your TLD - Top Level Domain
2.  .example.com is going to be your second level domain.
3. .www.example.com -- sub domain
4. .api.www.example.com -- Is your domain name
5. http : Part of it is the protocol that you want to use.

 

Lets see how DNS works . We have a Public IP it can be EC2 Instance for example . This can be accessed using example.domain name . So we are going to register this domain name for one of servers for our DNS .

Lets see how our browser can access it an get that response . So your web browser wants to access example.com . And to do so it is going to ask its local DNS server , hey do you know what example.com is . Now this local DNS server is managed by your company and assigned by your internet service provider dynamically.

And it the local DNS server has not seen this query before it is going to contact the root DNS server managed by the ICANN organization and your root DNS server says I have never seen it by I know .com . ".com" is an NS record Nameserver NS.1.2.3.4 -- the root DNS server says I dont know this answer but i can get something close to this what you are asking for . I know the .com domain and the .com domain has this IP.

So the local DNS says okay I am going to ask the top .com domain with the IP address 1.2.3.4 . This is managed by IANA . And the example.com is going to be asked to this DNS server . It says that I do know about example.com but I dont know , i dont have the answer to the query right away , dont know which record it is. But there is server called example.com that I know about. which is at 5.6.7.8 which is a public IP.  That you should ask your question for the answer . Then the local DNS server is going to go to the final server which  is the sub-level Domain of the DNS and this is the Domain that is going to be managed by your Domain Registrar . So it could be  for example Amazon Route 53

And the DNS servers asks do you know the example.com And the DNS server will have an entry for example.com . so it will hey of course I know example.com

I know it is a A record and the result of it is 9.10.11.12 . Now your Local DNS server know the answer after recursively asking the DNS servers and finding the most specific one. So it says that I am going to Cache that information right away for I can server this answer for future requests . So it is going to send back the answer to the webbrowser .

86. Route 53 Overview :

Authoritative DNS : Which means as a customer you can edit the DNS, which mean you have full control over this DNS. 

The idea is that you have a client that wants to access example.com but your EC2 only knows a Public IP .

Therefore we are going to write some DNS records into Route 53 into a hosted Zone. And when the client is asking for an example.com  . Then the route 53 service will be able to say her you are looking for the following IP address.
 

Then the client will be able to connect directly into our EC2 instance .

1. So Route 53 is also a domain registrar so  you will be able to register your own domain names there such as example.com  
2. We also have the ability to check of health of the resources using route 53 . 
3. And this is the only service in AWS which will provide 100% availability SLA.
4. Why is it called Route 53 , well Route 53 is a reference to the traditional DNS port
   

• In Route 53 you are going to define a bunch of DNS records . And these records define how you want to route traffic to a specific domain.
• Each record is going to contain a lot of information such as the domain name and the sub-domain such as example.com
  Record tyoes , eg A or AAAA, lets see what type of record is available to us.
•  And then the value of the record such as eg 123.456.789.101
• Routing Policy : How route 53 will respond to queries .
• TTL (Time-to-Live) : The amount of time the record is going to cached at DNS Resolver . Also called Time to Live
  
• Route 53 support the following DNS record types.

Lets learn the important type of record types that we need to know from an exam perspective .

 

 

 Lets have a look at what are hosted Zones . For any hosted zone you are going to create in AWS you are going to pay 0.50 cents . So this is not free to use Route 53 . And if you are about to register a domain name as i will in the hands on. This will cost you at least $12 per year .

87. Route 53 - Registering a domain

 

Lets Open the Route 53 service  which is a scalable managed DNS system . 

So lets go to the left hand side and Registered Domains . Go to Domains on the left click on Registered domains

 

 Register the domain .

 First we need to choose a domain

 

 

 So lets add this to Kart , then you have to specify the contacts for your domain,

 

 Once the purchase is made . You should be ready to go .

And finally from there you can go into your hosted-zone

And you should see a new Hosted_zone for your domain name. And in this hosted zone if you click on it . You care going to have the NS records.

88. Route 53 - Creating our first records

Now lets go- ahead and create our first records in Route53 , so I am going to go into my hosted Zone. And in there I am going to create some simple records

Create Record 

 And in here I can just have a record name 

 And now u need to specify your record Type.

But for now I will keep it simple I will keep it as A record . That is route domain name into an IPv4 address .