Event ID 30 — NLB Dedicated IP (DIP) Addresses Functionality

Applies To: Windows Server 2008

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.

 

Event Details

Product: Windows Operating System
ID: 30
Source: Microsoft-Windows-NLB
Version: 6.0
Symbolic Name: MSG_WARN_DED_NET_MASK
Message: NLB cluster [%2]: The dedicated network mask %3 is invalid. The cluster will converge and operate normally without this dedicated IP (DIP) address. However, if this DIP is required for remote cluster management, make sure that the dedicated network mask for the DIP is specified in a valid format.

Resolve

Ensure that the dedicated subnet mask is valid

If the dedicated subnet mask is not valid, the Network Load Balancing (NLB) cluster will converge and operate normally without the subnet mask. However, if the subnet mask is required for remote cluster management, make sure that it is specified in a valid format.

You should verify that the dedicated subnet mask is correctly specified.

When you are using NLB Manager, you must be a member of the Administrators group on the host that you are configuring, or you must have been delegated the appropriate authority. If you are configuring a cluster or host by running NLB Manager from a computer that is not part of the cluster, you do not have to be a member of the Administrators group on that computer.

To ensure that the dedicated subnet mask is correctly specified:

  1. 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.
  2. If NLB Manager does not already list the cluster, connect to the cluster.
  3. Right-click the host that you want to configure, and then click Host Properties.
  4. Click the Host Parameters tab, and, in Subnet mask, verify that the subnet mask is correctly specified. The mask should be entered in standard Internet dotted notation (for example, 255.255.255.0).

 

Verify

When you are using nlb.exe, you must be a member of the Administrators group on the host that you are configuring, or you must have been delegated the appropriate authority. If you are configuring a cluster or host by running nlb.exe from a computer that is not part of the cluster, you do not have to be a member of the Administrators group on that computer.

To verify that the dedicated IP address can be reached:

  1. Open an elevated Command Prompt window. Click Start, point to All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
  2. Type nlb.exe display,which displays extensive information about your current Network Load Balancing (NLB) parameters, cluster state, and past cluster activity. The registry information retrieved by the display command shows what the next state of NLB would be if a reload or some other operation that causes the driver to read the registry were to be performed.
  3. Type nlb.exe params, which displays information about your current NLB configuration, including the dedicated IP addresses used by the NLB driver.

 

NLB Dedicated IP (DIP) Addresses Functionality

NLB Cluster