Load testing the network
Sometimes network problems only appear under peak load conditions. Instead of waiting for those conditions to occur naturally, create them yourself by using the Traffic Generator tool. Doing so helps reveal problems in your network.
Prerequisite(s):  
Classic mode must be enabled.
 
To use the Traffic Generator tool, you must be using a local probe instance. The probe instance on which you want to generate traffic from cannot be on a remote system.
The network adapter must be capable of generating sufficient traffic to heavily load the network. For example, a 100 megabit NIC cannot use more than 10% of a 1 Gb network’s bandwidth.
The Traffic Generator tool allows you to load test (stress) your network by generating packets of a certain type and size, at the frequency you specify, sent toward a specific device or device group.
Caution: Be careful when generating traffic. Generating too much traffic can slow down the network. This is especially true using the broadcast destination (default), as packets are sent to every switch port of every switch in the broadcast domain. Be aware of what you are doing, and perhaps notify your users of possible downtime.
To use the Traffic Generator tool:
On the Classic tab, in the Tools group, click Traffic Generator.
 
When generating traffic it is best to view the generated traffic, including results, from a station separate from the Observer station generating the traffic.