The dedicated IP addresses in Network Load Balancing (NLB) must be properly configured and be able to contact individual NLB cluster hosts. If the dedicated IP address is not configured correctly, you cannot use it to manage the host or for other non-cluster-related communication.
Ensure uniqueness of dedicated IP addresses
All dedicated IP addresses must be unique in a Network Load Balancing (NLB) cluster.
To ensure that the dedicated IP addresses are unique:
Click Start, click Administrative Tools, and then click Network Load Balancing Manager. You can also open NLB Manager by typing Nlbmgr at a command prompt.
If NLB Manager does not already list the cluster, connect to the cluster.
Right-click the host that you want to configure, and then click Host Properties.
Click the Host Parameters tab.
In IP address, verify that each dedicated IP address is unique. If there are duplicate IP addresses, enter a different IP address.