Networking Operating Systems

Setting up a DNS Round Robin in Windows

A round robin lets you load balance by pointing the same host name to multiple servers in DNS.  As long as round robin service is enabled in the DNS server, incoming requests will be spread among the servers.

Following is the short version of how to do this.  For a more comprehensive look at this, see Rodney Buikes excellent article on the subject.

  • In the DNS Mgmt application on your DNS server, right click the server name in the tree in the left pane, select Properties, select the Advanced tab, ensure that ‘Enable round robin’ is selected.
  • Add HOST(A) records in the appropriate forward lookup zone, pointing to the servers to be covered.
  • If you want a little poor-man's fault tolerance, ensure that the TTL of each record is set to a short period of time, i.e. 15 seconds.  This ensures that if one of the servers fails, repeated attempts to connect will soon hit another server.