What command line tools are good for reliably monitoring network activity? I have used ifconfig, but an office colleague said that its statistics are not always reliable. Is that true? I have recently used ethtool, but is it reliable? What about just looking at /proc/net 'files'? Is that any better? EDIT I'm interested in packets Tx/Rx, bytes Tx/Rx, but most importantly drops or errors and why the drop/error might have occurred.