In this video, see how the DNS options are configured within AWS. Learn how to plan well for DNS and DHCP in your AWS solution designs.
- You know what DNS is if you looked at the previous episode. Now it's time to see how AWS just uses DNS and how you can maybe influence its use of DNS throughout the AWS environment. Because sometimes the way it uses DNS is well, the way you might expect a computer to use DNS. In other words, the stuff that happens automatically with DNS throughout AWS is just that, it's automatic. A computer generates it. And sometimes when computers generate things, they generate things that are easy for computers to understand, but not so easy for us humans. So, let's take a look at what it does with DNS out of the box and in this process you'll be seeing some good design things that you might want to do when you're building out an AWS site, to make sure that it's actually human-friendly and usable by the end users. Let's take a look at it. And the first thing I want to show you is immediately we go into IAM, Identity and Access Management. One of the first things you'll notice is right up here at the top, it tells you here's the link that users can use in order to sign in to AWS. So, all they have to do is remember the number 989745111221. That's all. As long as they remember that, they can sign in. You see this is what I mean by a computer generates a DNS name, that's what we have here. We actually have a host name. So this is a host name that a user can put in in order to try to authenticate. It's not very easy to remember that host name, though. Now, of course, they could have a link, and they've favorite it, and then they can just go to their favorites or their bookmarks and they could get to it, but that is really challenging. It's far better to rename this. And guess what? Amazon realized you're probably going to want to do that, so out to the right, you see a customize option. When you click that, you can give this an alias that maybe it's a little easier for you. So you might decide to say this is going to be the totalsemaws. And that's what you're going to use in this case, for the AWS login. We click yes, create, and it comes back with a new link that's a lot easier to remember. It's still longer, but remembering this as opposed to remembering all of those numbers is a huge difference. Now I just go to totalsemaws.signin.aws.amazon.com/console. I know it's still painful, but it's not as painful as it would've been. Now we can take this further. We're going to be looking at Route 53 in another episode, and we could use Route 53 to go in and create an alias for this that allows you to go to something a whole lot easier. So a much shorter name that redirects to this, but already, this is a lot easier when it comes to DNS. I do want to point out that this alias that we just created does have to be unique globally with Amazon. So, for example, if I click customize, and say yes I want to delete that, it goes right back to the way it was. When I click customize again, if I put in something simple like login, right? Do you think maybe someone's already thought of that? Well, when I click yes, create, it says, "The account alias login already exists." If I say how about logmein, right? That's nothin' anyone would think of, is it? Let's see, yes, create. I still can't use it. So the point is, this is global, why? It's just putting it in front of signin.aws.amazon.com. Everybody's is in front of signin.aws.amazon.com, so yours has to be unique. Therefore, you've got to come up with something different. So if we go back to totalsemaws, and click on yes, create, it lets me do it. Why? Well, because I deleted it when I used it previously, and so it was available again and I can use it this time. So, keep in mind it does have to be unique globally for all Amazon AWS users, because they share one portion, this portion right here, is the same across all AWS accounts worldwide. So, now that we have seen that, let me show you another place where DNS crops up. If we go to our AWS services page, and go into EC2, you will see that for each instance, AWS automatically generates a public DNS. And we see it right here. So this particular instance is EC2-3-16-46-44.us/east/2.compute.amazonaws.com. And now I can breathe. Obviously, that's a very long name, again, and not one that you probably want to use on a regular basis. Well, you'll notice if I click on it, and I come down to the bottom section, right here's that public DNS. You can see that I can copy it to the clipboard, but I can't actually edit it, so it won't let me change this in any way. That's because this is generated automatically completely free for me, so I have a host name for this EC2 instance. The problem is it's not a very usable host name. So if I actually want to use this on the internet, what I can do is either take my public IP address that I'm using and then create an alias that points to that or remember, I can create CNAME alias and redirect to this with a shorter DNS name. And I can do that through Route 53. Keep in mind, I don't have to use Route 53 for that. I may have my own DNS hosting somewhere else as well, and I can go into that DNS and redirect to this particular instance from some external DNS. Because DNS is resolved on the internet, right? Not necessarily just within AWS. So I could use some other DNS hosting service and still point to this. The key is I cannot change that host name that's generated by AWS for me, but I can have a different host name that points to my public IP address. So as you can see, DNS is used throughout AWS just automatically. A lot of things have domain names created for them automatically, instantaneously, as soon as they're created. Those domain names are not always friendly, and sometimes we want to change them so that they're a little more user-friendly, and we can accomplish that with aliases. In the next episode, we'll see how we can begin to do that kind of thing with Route 53, the internal DNS service that's available to you in your AWS account right out of the box. (mellow music)
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