I would like to use DNS round robin on 2008 R2 for two web servers, same hostname but different IP addresses. Is there any way to know how the DNS server maintains/knows about round robin requests? For example the first request will be pointed to IP-1 and the second request to IP-2. Is there any way to know this information?

You can test it by using virtual name to remote desktop to the server First request will go to IP-1 and second request to IP-2

You can test it by using virtual name to remote desktop to the server First request will go to IP-1 and second request to IP-2

"There is no standard procedure for deciding which address will be used by the requesting application - a few resolvers attempt to re list to give priority to numerically "closer" networks. Some desktop clients do try alternate addresses after a connection timeout of 30-45 seconds. Round robin DNS is often used to load balance requests between a number of Web servers. For example, a company has one domain name and three identical copies of the same web site residing on three servers with three different IP addresses. When one user accesses the home page it will be sent to the first IP address. The second user who accesses the home page will be sent to the next IP address, and the third user will be sent to the third IP address. In each case, once the IP address is given out, it goes to the end of the list. The fourth user, therefore, will be sent to the first IP address, and so forth." Link here.

"There is no standard procedure for deciding which address will be used by the requesting application - a few resolvers attempt to re list to give priority to numerically "closer" networks. Some desktop clients do try alternate addresses after a connection timeout of 30-45 seconds. Round robin DNS is often used to load balance requests between a number of Web servers. For example, a company has one domain name and three identical copies of the same web site residing on three servers with three different IP addresses. When one user accesses the home page it will be sent to the first IP address. The second user who accesses the home page will be sent to the next IP address, and the third user will be sent to the third IP address. In each case, once the IP address is given out, it goes to the end of the list. The fourth user, therefore, will be sent to the first IP address, and so forth." Link here.

Hi, Thank you for the post. Round robin is not a perfect load balancing mechanism. It just rotates it based on client queries. By default, Windows Vista and Windows 2008 clients do not honor DNS round robin mechanism. http://blogs.technet.com/b/networking/archive/2009/04/17/dns-round-robin-and-destination-ip-address-selection.aspx If there are more inquiries on this issue, please feel free to let us know. RegardsRick Tan TechNet Community Support

Hi, Thank you for the post. Round robin is not a perfect load balancing mechanism. It just rotates it based on client queries. By default, Windows Vista and Windows 2008 clients do not honor DNS round robin mechanism. http://blogs.technet.com/b/networking/archive/2009/04/17/dns-round-robin-and-destination-ip-address-selection.aspx If there are more inquiries on this issue, please feel free to let us know. RegardsRick Tan TechNet Community Support