Dynamic DNS – CompTIA Network+ N10-006 – 1.3

One useful feature of DNS servers is the ability to dynamically update the DNS records as devices are added to and removed from the network. In this video, you’ll learn about dynamic DNS updating and the use of Dynamic DNS services.

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In a previous video, we talked about all of the different DNS records, and how you would reconfigure DNS records and edit your configuration files whenever you needed to update your DNS server. But what if you could have your in stations automatically reconfigure the DNS server so that you didn’t have to make any changes to that configuration file? And that’s exactly the way that dynamic DNS updating works. This is DDNS. This allows us to update these records in the DNS server in a process that is automated. But perhaps more importantly, it’s very secure when this happens.

We would use this, of course, when we have environments where IP addresses are changing a lot, which is exactly what you would see if you were using DHCP. These devices are changing IP addresses all the time. New devices are coming onto the network. Others are leaving. So this would be a very easy way to keep your DNS server updated.

This is very common to see in something like Microsoft Windows Active Directory. In that particular case, the domain controllers register in the DNS. And now, any of the devices that connect to the network are able to find a domain controller wherever it happens to be.

Another place we might take advantage of dynamic DNS configurations is at home. We may have services that we’re running at home that we might want to access from outside. And our IP address changes all the time. Our cable modem may be one IP address one day, and then the ISP may change the IP addressing another day. And it’s difficult to keep track of what the IP address might be. It would be much easier to simply assign a name to our cable modem. And then we simply provide the name wherever we happen to be. We would then use a dynamic DNS service to constantly update whenever that IP address changes. That way, you can go to one central place, and it’s going to know what your current IP address happens to be.

This is a capability that’s built into many of the cable modems and routers that we have configured in our small offices, home offices, or at home. And it makes it very easy for us to configure a remote site for the dynamic DNS, and to configure the names and authentications that we might use if we ever want to take advantage of that.

For instance, here is one from my old router. It uses a dynamic DNS servers that, unfortunately, isn’t even available any longer. But this is a good example, of www.dynedns.org the service provider. And then I would assign a host name, a username, and password to this. Of course, I would have needed to register at that dynamic DNS server first to get the username and password, and to register that name and simply copy this information onto my router. And at that point, my router and the dynamic DNS server are in constant communication. And if anything ever changes, it updates the IP address back at the dynamic DNS provider. Then, I can be in a coffee shop. I can be a hotel. And I can access my local network at home by simply providing the name and taking advantage of these dynamic DNS services.