Let's say I have a Linux machine that is being bogged down by some network traffic. Might be someone FTPing a large file to it, a bunch of people downloading a large file, etc.
What are some options I could use to determine this? I've looked over say the netstat man but I'm not sure if this would be exactly what I need. It could at least tell me the ports so I could tell if it's FTP or not, but wouldn't help if say a file was being DLed.