How To Perform Basic Network Load Balancing Procedures in Windows Server 2003

This step-by-step article describes how to perform basic Network Load Balancing procedures. When you use Network Load Balancing, you can spread incoming requests across many servers. When you do so, you can expand enterprise-wide services, such as Web servers, Terminal Services, and streaming media servers, to make sure that the services respond quickly, even under heavy loads.

Network Load Balancing automatically detects when a server stops responding and quickly reassigns client traffic among the remaining servers. This safeguard helps you provide uninterrupted, continuous service for your critical business programs.

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How to Perform Network Load Balancing Procedures

This section describes how to perform the following basic Network Load Balancing procedures:

• Stop Network Load Balancing
• Disable Network Load Balancing
• Enable multicast support

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To Stop Network Load Balancing

• At a command prompt:
  
  1. Click Start, click
     Run, type cmd in the
     Open box, and then click OK.
  2. Type wlbs stop, and then press ENTER.
     
     Cluster operations are immediately stopped on the local cluster host. If you want to stop cluster operations on all cluster hosts, type either of the following commands, where ip_address is the Internet Protocol (IP) address of the cluster and
     name is the name of the cluster:
     
     • wlbs stop
       ip_address
       
       -or-
     • wlbs stop
       name
• From the Network Load Balancing Manager utility:
  
  1. Start the Network Load Balancing Manager utility, and then connect to the cluster that you want to modify.
  2. Under the cluster container, click the host that you want to stop.
  3. On the Host menu, point to
     Control Host, and then click Stop.

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To Disable Network Load Balancing

1. Start the Network Load Balancing Manager utility, and then connect to the cluster where you want to remove Network Load Balancing.
2. Right-click the cluster, and then click Delete Cluster.
3. Click Yes to remove Network Load Balancing from all the hosts that are members of the cluster.

If you cannot use Network Load Balancing Manager, you can remove Network Load Balancing through the network connections properties of each host. To do so:

1. Log on to the host computer as an administrator, and then double-click Network Connections in Control Panel.
2. Right-click the local area network connection where Network Load Balancing is installed, and then click
   Properties.
3. Click Internet Protocol (TCP/IP), and then click Properties.
4. Remove the primary IP address for the cluster.
   
   If the primary IP address for the cluster is in the Advanced TCP/IP Settings dialog box, click Advanced, and then remove the primary IP address for the cluster, and then remove any other cluster IP addresses that appear.
5. Click OK, click OK, and then click Close to return to the Network Connections dialog box.
6. Right-click the local area network connection that you previously edited, and then click Properties.
7. Click to clear the Network Load Balancingcheck box, and then click OK.

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To Enable Multicast Support

1. Start the Network Load Balancing Manager utility, and then connect to the cluster that you want to modify.
2. Right-click
   clustername (where
   clustername is the name of your cluster), and then click Cluster Properties.
3. Under Cluster operation mode, click
   Multicast, and then click OK.
4. On the message that states that the traffic mode will be changed from unicast to multicast, click Yes.

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Troubleshooting

• When you use the wlbs stop command or when you use the Network Load Balancing Manager to stop a cluster host, client computer connections that are already in progress may be interrupted. To avoid interrupting active connections, use the
  Drainstop cluster control command.
• To start the Network Load Balancing utility at a command prompt, type nlbmgr, and then press ENTER.

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