We previously discussed how to install DNS role in Windows Server 2012. In this post, I will explain how to configure that dedicated DNS server as secondary DNS for redundancy.
Keep in mind that it is always a good practice to have a backup for every role you have on every server if applicable and if the resources are available.
Note: You will need access to your primary DNS server in order to finish setting up your secondary DNS
Launch your DNS Manager, can be found in your Start screen
Under your server name, right-click “Forward Lookup Zone”, then click on “New Zone…”
You will get the “New Zone Wizard” welcome screen, click Next
In the “Zone Type” screen, you will need to select “Secondary zone” as this will be your backup secondary DNS that will replicate from your primary DNS, click Next
Give your new secondary DNS zone a name, this is different than your server name, you can name it anything you want, but mostly it is a good idea to name it the same way your primary DNS is setup, or you can put your domain name
Now you need to put in your Primary DNS server name or IP address, this is where you tell your secondary DNS where to copy all the DNS info from. You will also need to make small adjustments to your primary DNS, we will cover that later on in this article
Once you put the IP address or server name, you will see the green check mark indicating that the server validated and it is ok to proceed, click Next
Lastly, verify your information and click Finish
Setting up the secondary DNS is done, but we are not entirely finished here, we need to tell our primary DNS that it is ok for this secondary DNS to pull information from it. Otherwise replication will fail and you will get this big red X
Head over to your primary DNS server, launch DNS manager, expand Forward Lookup Zones, navigate to your primary DNS zone, right-click on it and go to Properties
Go to “Zone Transfers” tab, by default, for security reasons, the “Allow zone transfers:” is un-checked to protect your DNS information. We need to allow zone transfers, if you value your DNS records, you do not want to select “To any server” but make sure you click on “Only to servers listed on the Name Servers tab”
Head over to the “Name Servers” tab, click Add
You will get “New Name Server Record” window, type in the name of your secondary DNS server. it is always better to validate by name not IP address to avoid future problems in case your IP addresses change. Once done, click OK
You will see your secondary DNS server is now added to your name servers selection, click OK
Now if you head back to to your secondary DNS server and refresh, the big red X will go away and your primary zone data will populate
Your secondary DNS is fully setup now. You can not make any DNS changes from your secondary DNS. Secondary DNS is a read-only DNS, Any DNS changes have to be done from the primary DNS.