Network Bandwidth per Application

Question

Level 1

8 points

Network Bandwidth per Application

Hi,

My broadband usage has gone from an average of 1.5GB per day up to 14GB per day from last week - even when there there's nobody at home. After an exhaustive process of elimination, I've deduced that my iMac is the cause. The challenge I have is that it's still churning through 0.5GB/hour when there are no visible applications open.

Is there an OSX utility or 3rd party piece if software I can use to determine which application is driving this network activity? And if it is some malware (I don't generally use the admin account) what software could get rid for me?

Thanks

Daniel

iMac G5, Mac OS X (10.4.9)

Posted on Apr 19, 2013 12:43 AM

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Answer 1

Apr 19, 2013 2:22 AM in response to DanielGrimes

I just discovered this myself:

open terminal
type: # nettop
use arrows to scroll up and down, close and expand

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Answer 2

Apr 19, 2013 2:39 AM in response to Midge 't Hoen

WOW, great hint.

You never stop learning 😉

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Answer 3

Linc Davis

Level 10

209,739 points

Apr 19, 2013 11:57 AM in response to DanielGrimes

Most often iCloud is involved in cases of mysterious bandwidth use. If you use iCloud, uncheck at least Photo Streamand Documents & Data in its preference pane and see whether there's any change.

Otherwise, there's no easy way to monitor network usage per process using built-in tools. If you're an advanced user and you want to try, see the manual page for the nettop(1) shell command. It may not be able to provide the information you're looking for.

The third-party products Rubbernet and Little Snitch are supposed to record network usage by processes. I can't vouch for them. Both were available as free trials, the last time I checked. I suggest you uninstall either one when the question has been answered.

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Answer 4

DanielGrimes Author

Level 1

8 points

Apr 22, 2013 5:16 AM in response to DanielGrimes

Thaks for the help - nettop was a bit too difficult to understand; I tried disabling foro stream etc, but no change. Rubberband was great the first time, but has stopped working. Little Snithch isn't very clear; I think it's doing some interesting stuff, but I don't understand.

Interestingly, whenever I use the computer, the bandwidth usage goes down...I think I'll buy the full version nr rubberband and I can leave it on over 24 hours etc and see what happens.

I'm starting to think the issue must be with the ISP again!

Thanks so far

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Answer 5

Linc Davis

Level 10

209,739 points

Apr 22, 2013 6:14 AM in response to DanielGrimes

My guess is that you have a cloud backup client running.

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Answer 6

Apr 22, 2013 7:18 AM in response to DanielGrimes

Go to the system preferences, and list in a reply here the items listed or enabled in the following locations:

1. Users & Groups system preferences > Your account > Login Items tab (any login items listed?)

2. iCloud (any checked items here?)

3. Anything in the "Other" section of the system preferences.

4. Any menu extras you have in your OS X menu bar (at the top-right of the menu bar)

Does the system use network resources when your account is logged out? Since it is using so much anyway (~500MB/hr), try checking your network usage both with it logged in to your account for an hour or two, and then with it logged out and sitting at the login window.

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Answer 7

DanielGrimes Author

Level 1

8 points

Apr 23, 2013 12:03 AM in response to Topher Kessler

Thanks for your advice. I logged out and usage from midnight to 6am reduced from the usual 4.5GB to 0.5GB.

0.5GB is still a decent amount of data considering there was no one logged into the computer. Could there be a problem with the Airport base station?

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Answer 8

Apr 23, 2013 6:34 AM in response to DanielGrimes

There could be, but you need some way to list the programs and processes that are using network activity; otherwise, it's just going to be a guessing game as to what is the cause. After the system has been running for a while with your account logged in, open the Terminal and run the command "nettop" and then press the left arrow to collapse the view a bit. Then expand the window so you can see more columns of the "nettop" output, and it should show you various details of what is going in and out of your system. Expand the view until you can see both "Bytes In" and "Bytes out" and compare the values in these columns for the processes listed, to see which ones are largest. The values will be in bytes, with "KiB" and "MiB" next to the numbers representing "kibbibytes" and "mibbibytes" (similar to Kilobytes and Megabytes in difference).

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