To add Host (A) DNS records manually to the DNS database, administrators must follow the steps given as below:
1. Log on to Windows server 2008 R2 DNS server computer with domain admin or enterprise admin credentials.
2. From the desktop screen, click Start.
3. From the Start menu, go to Administrative Tools > DNS.
4. Expand the DNS server name.
5. From the expanded list, double-click Forward Lookup Zones.
6. Select the DNS zone that the A record needs to be added. (Needs to be the domain that you have provided in the FQDN or the domain that your users will use for authentication)
7. Once selected, right-click the DNS zone.
8. From the displayed context menu, click New Host (A or AAAA).
9. On New Host box, type in the Fully Qualified Domain Name (FQDN) along with the IP address of the target host computer in the Name and IP address fields respectively.
10. Check the Create associated pointer (PRT) record box.
11. Once done, click Add Host.
11. On the displayed message box, click OK.
12. Back on the New Host box, click Done.
13. Close DNS Manager snap-in when done.