Little Snitch: Can also be used to monitor network activity per application

Posted by Pierre Igot in: Macintosh
April 16th, 2008 • 9:50 am

I am a long-time user of Little Snitch, not because I am paranoid, but because they are out there.

By this, I mean that there are a number of applications and sites that do attempt to establish connections behind the user’s back, without the user’s prior permission. Once Little Snitch is installed and running, this becomes abundantly clear.

I don’t mind a Mac OS X application connecting to a server owned by the application’s developer via http on port 80. This is a common procedure used by application developers to enable their application to check for available updates.

But I do very much mind applications connecting to third-party servers to transmit information without my prior approval. And the recent story with Adobe and Omniture proves that users have reasons to be suspicious of the practices of application developers.

Yes, in order to work its magic, Little Snitch does need to install a kernel extension in Mac OS X’s “System” folder, and that does bother me a bit. But in truth, in several years of constant use of Little Snitch, I have yet to encounter a single bug, and I have yet to see a single report of Little Snitch having a negative impact on the stability or reliability of Mac OS X.

But my point today is not about Little Snitch’s main function, which is to intercept unauthorized outgoing connections. My point is that I recently discovered that Little Snitch has another feature that I actually find quite useful.

See, I still have to live with limited bandwidth, because my Internet connection is with a satellite Internet service provider. And because of this, I need to be able to monitor incoming and outgoing Internet traffic on my machine.

For many years, I have used MenuMeters for this purpose. MenuMeters resides in my menu bar (which is fairly long with tons of room, since I have a 30″ screen) and is visible at all times, unlike Mac OS X’s own Activity Monitor, which also enables you to monitor network traffic, but only in a window. Also, MenuMeters provides more flexibility and more options than Activity Monitor.

But MenuMeters, like Activity Monitor, suffers from one significant limitation: It can only report on overall incoming and outgoing Internet traffic. It cannot tell you where this traffic is coming from, i.e. which application is causing it. More often than I would like, I find myself in a situation where there is incoming Internet traffic, and I have so many applications open and running that I am not sure which application is causing the traffic.

That’s where Little Snitch comes in. In addition to its main feature, Little Snitch actually also includes a feature called “Network Monitor,” which can be accessed through Little Snitch’s menu extra in the menu bar:

Menu Extra

And this Network Monitor feature does not just show overall incoming and outgoing network traffic. It can actually show a breakdown of the incoming traffic per application, in a small floating window that you can keep open in the foreground at all time:s

Network Monitor

I find this feature particularly useful in my situation with limited bandwidth, where I really do need to know where the incoming traffic is coming from and what application is causing it. I suppose that, when I finally get a proper high-bandwidth connection, I will care less about those things, because background network traffic will have little impact on what I am doing with the foreground application.

But until then, Little Snitch’s Network Monitor is definitely a very useful addition to my panoply of monitoring tools.


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