You are the network administrator for your company. The network consists of a single Active Directory domain. All computers on the network are members of the domain. You administer a three-node Network Load Balancing cluster. Each cluster node runs Windows Server 2003 and has a single network adapter.
The cluster has converged successfully. You notice that the nodes in the cluster run at almost full capacity most of the time. You want to add a fourth node to the cluster. You enable and configure Network Load Balancing on the fourth node. However, the cluster does not converge to a four-node cluster. In the System log on the existing three nodes, you find the exact same TCP/IP error event.
The event has the following description: “The system detected an address conflict for IP address 10.50.8.70 with the system having network hardware address 02:BF:0*32:08:46.” In the System log on the new fourth node, you find a similar TCP/error event with the following description: “The system detected an address conflict for IP address 10.50.8.70 with the system having network hardware address 03:BF:0*32:08:46.” Only the hardware address is different in the two descriptions. You verify that IP address 10.50.8.70 is configured as the cluster IP address on all four nodes.
You want to configure a four-node Network Load Balancing cluster.
What should you do?
A.
On the fourth node, run the wlbs.exe reload command.
B.
On the fourth node, run the nlb.exe resume command.
C.
Configure the fourth node to use multicast mode.
D.
Remove 10.50.8.70 from the Network Connections Properties of the fourth node.
Explanation:
This normally happens when you do not enable the Network Load Balancing (NLB) service in TCP/IP of the server, when adding two IP’s (one for the server and one for the load balancing IP). When you want to manage a NLB cluster with one network adapter, you use the multicast option. Since reload/suspend and remove the IP are all garbage answers, it could be that the other nodes are using multicast, and this new node is using unicast. That is why, on a single network adapter configuration, it will cause an IP conflict.Reference:
Deborah Littlejohn Shinder, Dr. Thomas W. Shinder, Chad Todd and Laura Hunter, Implementing, Managing, and Maintaining a Windows Server 2003 Network Infrastructure Guide & DVD Training System, Syngress Publishing Inc., Rockland, 2003, p. 689
http://www.microsoft.com/ windowsserver2003/techinfo/reskit/resourcekit.mspx.