Instructor: Okay so let's talk about Route53.
So Route53 is a managed DNS.
And DNS stands for Domain Name System.
And what's an DNS overall?
Well it's a collection of rules and records that will
basically help a client understand how to reach a server
through URL's.
So think of it as what it says it's
routing clients to final addresses.
So an AWS, you have a lot of DNS records available
but the commons that will be asked of you is going to be:
A which is a URL to an IPv4 IP.
AAAA which is a URL to an IPv6 type of IP.
CNAME which is mapping a URL to URL.
And Alias which is mapping a URL to an AWS resource.
Now we'll see CNAME versus Alias in detail in a later
lecture, but for now, remember,
there's just these most common records.
So how does a DNS work?
Well say a web browser wants to talk to an application
server and the application server is at this IP:
32, 45, 67, 85.
What we'll do, is the first thing we'll have to do is
to talk to Route53, and that goes on behind the scenes.
Doesn't mean we have to do the basically, that's how
the whole internet works.
So our browser will make an DNS request say for
myapp.mydomain.com and the Route53 will reply and say
by the way in my records it looks like this domain
has this IP address in A record because I send back in IP.
So URL to IP mapping and I send back the IP 32.45.67.85.
Okay so now my web browser has done the DNS request
and has gotten back an IP from it.
So now it knows directly to make an HTTP request directly
to the IP and it will reach the application server.
And it will say, by the way, the host name it asked for
is myapp.mydomain.com.
And then the application server will just reply with
HTTP response.
So this is how DNS works.
Obviously it's way more complicated but that's the
simplified version.
The first thing that happens is that there's an DNS
request and then there's an HTTP request.
So Route53 can use different things.
It can use public domain name that you own or buy,
and then you can have whatever you want:
application1.mypublicdomain.com.
Or a private domain that can only be resolved
by your instances within your VPC.
So for example, this domain application
application1.company.intneral, that's not something you can
purchase on the internet.
You'll have to make this a private domain and that's
only your applications can resolve this thing.
Now Route53 has a lot of advanced features.
Some will be load balancing and we'll see it how that works
through different kind of records.
There will be health checks
and we'll also see this in details.
And then there's routing policy as we'll see on details
such as simple, failover, geolocation, latency, weighted,
and multi value.
So last thing you should know is that you are going to pay
$0.50 per month per hosted zone.
So Route53 is not something that's free.
There's no free tier and if you go ahead with this tutorial
and buy a domain name you will also have to pay for that
domain name about $12.
So just so you know, if you go along with me with this
lecture then you'll have to pay a little bit of money.
So that's it for the overview, we'll do a deep dive into
menu of these advanced features as well.
But for now let's go ahead and create a domain a domain
name and try out a small record.