In the previous installment of this article you learned that Network Monitor can be used to monitor cluster communication and how to install the tool. Now we will take a look at how you can use Network Monitor and the type of traffic you should be looking for.

Once Network Monitor has been installed, it can be used to monitor traffic on the private cluster network. To start a new capture in Network Monitor:

1. Click Start, point to Administrative Tools, and click Network Monitor.

2. From the Capture menu, click Start.
3. Be sure to select the network adapter connected to the private cluster network.
4. To end the capture, click Stop and View from the Capture menu.

Network monitor will display the network traffic sent to and from the computer. Cluster Service uses UDP port 3343 to send and receive heartbeat messages. You can set up a filter in Network Monitor to only display the pertinent UDP traffic.

System Monitor can also be useful for monitoring certain aspects of cluster communication, such as RPC performance. By monitoring the counters included with the Redirector object, you can test the network connectivity between cluster nodes as well as the speed of the network connection. To monitor RPC performance, you should monitor the following Redirector counters:

• Bytes transmitted/sec

• Bytes received/sec
• Bytes total/sec

You can locate these counters in System Monitor by following the steps listed below:

1. Click Start, point to Administrative Tools, and click Performance.

2. Select System Monitor.
3. Right click within the right pane and click Add Counter.
4. Select Redirector from the Performance Object drop-down list.
5. Click the Select counter from list option.
6. Highlight a specific counter and click Add.
7. Repeat step 6 for each counter you want to monitor.
8. Click Close.

[tags]monitoring cluster node communication,traffic monitor,redirector object,rpc performance,system monitor[/tags]