- Block Outgoing Connections
- Block Outgoing Connections Mac Little Snitch
- Block Outgoing Connections Mac
It’s been four years since we explained how to block outgoing connections on a Mac using a third-party tool (TCPBlock), but Apple still hasn’t offered any built-in solution to deal with this task. While you can easily block all incoming connections using the built-in firewall, there is still no way to deal with outbound connections. While you can still download TCPBlock from this link, you should look for better alternatives since it hasn’t been updated in over five years.
Donit let the fact that the developer is in Austria concern you; theyire the good guys. Once Little Snitch is installed, it will monitor all outgoing connections. You can set rules for trusted.
We also explained how to use Little Snitch 3 to block outgoing connections on a Mac, but here we want to present some better and up-to-date alternatives so that you can choose what is best for you.
Unfortunately, until Apple comes up with a solution, OS X users will have to continue using workarounds or dedicated third-party tools for this purpose.
Block outgoing connections on Mac
Several alternatives exist to block outgoing connections on OS X, and here we present a few so that you can choose the one you think best suits your needs.
The program has a couple of different useful modes. The first is a little yellow icon which completely blocks incoming connections while the red button will block outgoing connections. Overall, this application is both lightweight and useful. It is fast because it uses your built-in firewall and provides sufficient Internet traffic protection. Maximum number of connections are impacted by certain limits on both client & server sides, albeit a little differently. On the client side: Increase the ephermal port range, and decrease the tcpfintimeout. To find out the default values: sysctl net.ipv4.iplocalportrange sysctl net.ipv4.tcpfintimeout.
The first solution makes use of the Mac Terminal to block outgoing connections, meaning it doesn’t require you to install any third-party tools. The downside is that it is a slightly less user-friendly solution.
The second solution is to let a program do the hard work for you. There are many tools available for download, either for free or for a one-time fee.
Let’s start by taking a look at the first option, how to block outgoing connections from the Terminal
Block outgoing connections using the Terminal
In order to block outgoing connections using a Terminal, you need to know the specific IP address associated to the service you want to block communication with. There are several ways to find your target IP address. One way is to monitor all open connections in OS X with the lsof -i Terminal command. If you are sure how to get this information don’t worry, you can just proceed to the next section that makes use of third-party tools to block specific outgoing connections. If you, however, happen to know the exact IP address you want to block, this solution might be the perfect fit for you.
Even though the process may not be familiar to you, especially if you’re not used to using the Terminal, it is a fairly straight forward procedure to follow. To configure your Mac to block a specific outgoing connection, proceed as follows:
- Open the Terminal.
There are multiple ways to do this: one way is to open your Applications folder, then click on Utilities and finally on Terminal. A faster way is to launch Spotlight by pressing Cmd + Space, type “Terminal” in the bar and double-click the search result. - Create a backup copy for the hosts file.
Type (or copy and paste) the following in the Terminal you just opened: