Windows NT Load Balancing Service Remote Control Commands Fail (192467)

SYMPTOMS

When Windows NT Load Balancing Service (WLBS) remote control commands are invoked from a system outside the cluster, no response is received from one or more cluster hosts.

CAUSE

This problem can be caused by one of the following:

The cluster network interface cards (NICs) are not reachable from the outside system. If you have multiple NICs on a cluster host, the dedicated NIC may be on a separate subnet from the cluster NIC. If you invoke a remote control command from an outside system on this subnet, the cluster NICs and WLBS driver will not receive the command.
Remote control commands are sent to a secondary cluster IP address. Commands must be sent to the cluster's primary IP address (which is entered in the WLBS Setup dialog box).
WLBS's UDP control port is blocked by a firewall. By default, remote control commands are sent to UDP port 1717 at the cluster IP address. You can also change the port number by modifying the corresponding WLBS registry parameter.

RESOLUTION

To resolve this issue, use one of the following methods that correspond to the cause listed above:

Be sure that the cluster NICs on the cluster hosts can be reached by the outside system. -or-
Be sure that you send remote commands to the secondary cluster IP address. -or-
Be sure that UDP port 1717 has not been blocked by a router or firewall.

MORE INFORMATION

The Windows NT Load Balancing Service is configurable from a remote location by copying the control program (WLBS.exe) to any Windows NT device.