Network drivers may be tested using standard network utilities. ftp(1) and rcp(1) are useful because the files can be compared on each end of the network. The driver should be tested under heavy network loading, so that various commands can be run by multiple processes. Heavy network loading means:
Traffic to the test machine is heavy.
Traffic among all machines on the network is heavy.
Network cables should be unplugged while the tests are executing to ensure that the driver recovers gracefully from the resulting error conditions. Another important test is for the driver to receive multiple packets in rapid succession (back-to-back packets). In this case, a relatively fast host on a lightly loaded network should send multiple packets in quick succession to the test machine. It should be verified that the receiving driver does not drop the second and subsequent packets.
These types of devices are usually STREAMS based.