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Add a firewall your Mac system. Whether you want to know which programs are using your network or block certain applications from using it out altogether, Little Snitch is the Mac firewall you’ve been looking for.
We’ve shown you how to enable the included firewall in OS X, but it’s quite limited. It allows you to block traffic on a per-app basis, but beyond that there’s not a lot of configuration options. You can partially correct this with software like Icefloor, which gives you more control over the Mac firewall, but software like this isn’t entirely user-friendly.
Little Snitch, in contrast, is easy to use by default but also provides access to advanced features – such as system-wide rules and a handy network monitoring tool.
As A Firewall
Install Little Snitch and you’ll need to reboot. When that’s all done, you’ll immediately start seeing notifications like this:
An application – in this case, Bittorrent Sync – wants to use the Internet, so Little Snitch lets me know. It also gives me the option to allow or block. This is quite standard firewall functionality, and allows you to decide which apps should and shouldn’t have the right to use the Internet. In this case the app is useless without a network connection, so I allow. I can do so for this particular URL, for the entire domain or even for any and all network connections – it’s all about what I’m comfortable with.
Why not allow every app to use the network? Maybe I don’t see a reason to. Maybe I don’t want certain apps to update without knowing, because they’ll break. Or maybe I just like being asked first. Whatever your reason for wanting control is, Little Snitch can help you out.
Want to change any of the rules you’ve set up? You can do that in the “Rules” section, which you’ll find after clicking the menu bar icon:
Here you’ll see what you’ve allowed and blocked. Delete a rule if you want to be asked next time, or change the rules however you like.
As A Network Monitor
Even if you’re not interested in a full-blown firewall, Little Snitch still has its uses. The built-in monitor – accessible by default by simply hovering over the menu bar icon – shows you which apps are using your network connections and which domains they’re connected to.
You can expand any individual apps, to check out which URLs have been recently accessed:
This is useful if you want to learn which apps are talking to which sites, or if your Internet connection is slow for unexplained reasons (maybe an app is using up all of your bandwidth without your knowledge).
If you’re using Little Snitch on a Macbook, you probably use a variety of different networks. You can create profiles with different rules for different networks. This is a good idea, because there are probably some apps that you’d like to allow Internet access to at home that you’d rather block in a coffee shop.
There’s a lot more functionality here, the app is well-designed in that it includes advanced features but does not push them on users they might confuse.
Download Little Snitch
Ready to check this out? Go ahead and download Little Snitch. Be warned, though: you’ll only have the demo before you pay.
About The Demo
The full version isn’t free – it starts at $35 – but if you want to control which applications can and cannot use your Internet connection there’s no better tool. The demo is perfect if all you want is to discover which apps are most using your Internet connection. With it you can indefinitely monitor your Internet connection, but blocking will only work for three hours at a time.
If you want to block Internet traffic you’ll need to pay for the full version, but if you just want to check out which apps are using your network the demo will always work for you.
Why use a firewall at all? There’s security, of course, but there’s also the idea that you should have control of what you computer says to the outside world. The 10th Anniversary page on the Little Snitch website offers these three questions, which led to the development of the app:
- Why does my router’s network LED blink on every occasion, although I’m not actively working on my computer?
- Is it really necessary, that programs periodically connect to the vendor’s server for software update checks, which yields a detailed statistics about when and how often I use their program?
- Is it really in my interest that programs have the ability, without being asked, to send arbitrary, often even personal or confidential information from my computer to unknown third parties on the Internet?
If these questions resonate with you, a firewall is probably a good idea. If not, I suppose there’s no need to look into this app. Let me know what you think.
Download: Little Snitch for Mac OS X (free demo, licenses start at $35)
Do you think firewalls are relevant in this age of always-on networking? Leave your thoughts below.