How to find source and targhet of data transmissions

Karl Auer kauer at
Sat Mar 2 11:18:44 UTC 2019

On Sat, 2019-03-02 at 18:33 +0800, Bret Busby wrote:
> For the past few minutes, the System Monitor shows data being
> downloaded, that I have not authorised, and about 300-500 kB/s.
> How do I find where the data is originating, and, what is downloading
> it?

If it's arriving at your computer, you know the target.

To find the source, install and run wireshark on your system. When it
starts, select the primary interface on your system and click the blue
fin at top left to start capturing packets. After it's been capturing
data for a few minutes, click the red square to stop capturing. Then
use the "Statistics" feature to list top talkers. Go to Statistics ->
Endpoints and click on the IPv4 tab. You can then click on the column
headings to order the list in various ways. For example, click on "RX
Bytes" to order by data volume received.

If you are using IPv6, also check the IPv6 tab...

Remember the values in the columns related to the addresses in the
leftmost column. Your own address will probably be the one that sends
and receives most, so you are really looking for the next chattiest :-)

Regards, K.

Karl Auer (kauer at

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