How to Enable Round Robin on the DNS Server to Balance Load

The Microsoft DNS Server supports round robin, which is a technique used for balancing the load between servers. This feature enables DNS to send both IP addresses when a query is received for myserver.mydomain.com. The client (or Resolver) always uses the first one. The next time when DNS receives a query for this name, the order of the IP address list is changed using round robin method (the address that was first in the previous list is last in the new list). Round Robin of name records is not supported because only one canonical name is allowed for any one alias.

In the Appliance, you can add record(s) for all the IPv4 address to the Domain Name Service(DNS) Server to get load balance among the network interfaces.

For more information on load balancing between servers, refer to RFC 1794.

How to Add a Record for Additional IP Addresses to Domain Name Service Server

When a server has two or more network interface cards (NICs), or more than one IP address for an NIC, you can add a record for the additional IP address(es) to the DNS server by creating an "A" record for each IP address.

Example:

Consider that a server's DNS host name is <myserver> and DNS domain name is <mydomain.com>. This server has following two IP addresses assigned:

To add these IP addresses to the DNS Server, create two "A" records in the <mydomain.com> zone as below:

For the Resolver to get the same IP address every time, create two more "A" records assigning a unique name to each address as below:

Using this method, a Resolver always obtains IPAddress1 when sending a query for Altname1 and always obtains IPAddress2 when sending a query for Altname2.