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The purpose of the Interface Start / Stop test is to validate that the driver can successfully stop a network interface and restart it again. Testing the driver’s driver’s ability to stop the network interface is often skipped, but it is an essential function. Stopping and starting the network interface of your device is one of the ways to detect buffer leaks since stopping the device will deallocate all the network buffers and descriptors. If restarting the network interface fails, it might indicate that you have a buffer leak situation.
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In the example shown in Figure 8-5, the test result that shows "FAIL – – 1 1 1" indicates that the Interface continued replying to the test station host after it has sent the ifss stop command. Since all commands sent by the NDIT are acknowledged by the target, it is unlikely that the command wasn't received and processed by the target. Furthermore, the 100% success rate for the ICMP echo shows that the target is responsive. Therefore the error should be in the implementation of the NetDev_Stop() function.