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Stop or Start Handling Network Load Balancing Cluster Traffic

Applies To: Windows Server 2008, Windows Server 2008 R2

Use the following procedures to stop and start handling Network Load Balancing (NLB) cluster traffic. You might need to stop and restart NLB cluster traffic when:

  • Undertaking troubleshooting or maintenance operations.

  • Dealing with application issues on one or more hosts in the cluster.

  • Scaling down the cluster because the traffic no longer requires the current number of hosts.

Stopping or starting handling Network Load Balancing cluster traffic

  • Using the Windows interface

  • Using a Command Prompt window

To stop or start handling Network Load Balancing cluster traffic by using the Windows interface

  1. To open NLB Manager, 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 list the cluster, connect to the cluster.

  3. If you want to stop cluster operations on all cluster hosts, right-click the cluster, point to Control Hosts, and then click Stop.

    If you want to stop the cluster service on only a particular host, right-click the host, point to Control Host, and then click Stop.

  4. If you want to start cluster operations on all cluster hosts, right-click the cluster, point to Control Hosts, and then click Start.

    If you want to start the cluster service on only a particular host, right-click the host, point to Control Host, and then click Start.

Additional considerations

  • When you are using Network Load Balancing (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.

  • When you stop handling NLB cluster traffic, client connections that are already in progress are interrupted. To avoid interrupting active connections, consider using the drainstop cluster-control command (instead of the stop command), which allows the host to continue servicing active connections but disables all new traffic to that host.

  • You can restart cluster operations after stopping or suspending them. When you click Start on the cluster or host that you want to restart, it restarts cluster operations, but it does not enable the use of cluster-control commands, which have been disabled by a previous suspend command.

    For more information, see Additional references.

To stop or start handling Network Load Balancing cluster traffic by using a Command Prompt window

  1. To open a Command Prompt window, click Start, right-click Command Prompt, and then click either Run as administrator or Open.

  2. Type one of the following commands:

    • To stop handling all cluster traffic on this host, type:

      nlb.exe stop
      

      Or, if you want to stop cluster operations on all cluster hosts, type:

      nlb.exe stop <cluster IP address | cluster name> global
      
    • To start handling all cluster traffic on this host, type:

      nlb.exe start
      

      Or, if you want to start cluster operations on all cluster hosts, type:

      nlb.exe start <cluster IP address | cluster name> global
      

Additional considerations

  • When you are using Network Load Balancing (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.

  • When you use the stop command, client connections that are already in progress are interrupted. To avoid interrupting active connections, consider using the drainstop cluster-control command (instead of the stop command), which allows the host to continue servicing active connections but disables all new traffic to that host.

    For more information, see Additional references.

  • The stop command differs from the suspend command. The suspend command stops NLB on the host and suspends all NLB cluster-control commands on the host (except the resume and query commands). The Stop command stops NLB on the host but does not affect the other NLB cluster-control commands.

  • The start command can be used after a stop or suspend command. It restarts cluster operations, but it does not enable the use of cluster-control commands (including remote control commands), which have been disabled by a previous suspend command.

    For more information, see Additional references.

  • You should not use the start command to form a new cluster.

Additional references

Disable New Network Load Balancing Traffic Handling for Specific Ports

Suspend or Resume Network Load Balancing

Controlling Hosts on Network Load Balancing Clusters