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    I have a nice little headless Debian machine setup for small automated tasks.
But a few days ago i noted there is a big bandwidth RX on this one, more than the one predicted.
    I started iftop but now i only now to what ip's the bandwidth is coming from.

Question: How can i find what process is taking up the most bandwidth on this debian machine ?


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4 Answers 4

up vote 2 down vote accepted

In relation to the netstat solution by lg:

Once you know the port that the data transfer is using, you can use the lsof tool to find out the process.

lsof -i :6753

The command is a lot easier to remember, but on the downside lsof isn't installed on all systems by default.

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With iftop, press p to view the port; then with netstat -nutap | grep :PORT. In the last column you can see the process name.

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Install nethogs, it's like top but for network bandwidth.

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If you know the port used, you can figure out which daemon is using it. Alternatively, you can use pktstat to help. That shows you the port numbers.

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so i found out the port (i think) what about finding out what process is using it ... ? :D –  s.mihai Jul 30 '10 at 7:35
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