You can edit the hosts file using terminal, although I'd not recommend it if you're unsure what you're doing. But doing so you can block outgoing access to specified IP addresses or websites.
Apr 04, 2020 Your Mac’s hosts file is a small, but important text document that has the ability to map hostnames to specified IP addresses. Although the modern Internet uses a variety of public and private DNS servers to map IP addresses, the hosts file is a handy way to override those DNS servers, allowing you to manually point a website address to the desired IP address, or block access to a site. Sep 27, 2016 Im trying to block outgoing connections from my mac cause sometimes im using my iphone as a hotspot, and i have a limited data plan. I also saw an app called radio silence and it costs 3 times less than little snitch, will it do the same job? (deny apps to have internet connection unless i want them to be able to connect)? Radio Silence’s network monitor shows you every network connection in real time. If you find a misbehaving app, you can block it with a single click. Radio Silence exposes everything. Find the hidden helpers and background processes apps use to make connections: Helper apps and executables; In-memory processes; Daemons, XPC services, and more.
Windows Firewall Block Outgoing Connections
If you simply want to stop your mac connecting out, why do you not simply turn off your wifi so you're not connected to the internet?
Alternatively a GUI firewall like Little Snitch would be a better option as it gives you very granular options for blocking incoming/outgoing traffic and is fairly easy to use and set up.
Connection Blocking settings apply to the incoming and the outgoing connections that use a specific application, service, port, or IP address.
You can use the Connection Blocking window to configure whether an application or a service that is allowed to connect to the Internet or to the local network. You can select the required network location from the Editing settings menu and configure the Connection Blocking settings.
You can configure the Connection Blocking settings only if the Connection Blocking option is turned on in the Advanced window.
Block Outgoing Connection
You must have a user account that has administrator privileges to perform this task.
Block Incoming And Outgoing Connections
Start Norton.
If you see the My Norton window, next to Device Security, click Open.
In the Norton product main window, click Advanced or Settings.
On the left pane, click Firewall.
In the Connection Blocking row, click the settings icon.
In the Connection Blocking window, in the Editing settings menu, select the network location for which you want to configure the connection blocking settings.
Select an option in the View menu.
The options that appear in the View menu vary depending on the network location that you select in the Editing settings menu.
Your options are:
Applications
Lets you specify the Connection Blocking settings for the applications that run on your Mac.
Services/Ports
Lets you specify the Connection Blocking settings for the services and ports that run on your Mac.
Zones
Lets you specify the IP address to or from which firewall allows or blocks connections.
All, in order of precedence
Lets you specify the current Connection Blocking settings for the Applications, services, ports, and zones in the order of precedence.
Select one of the following tabs:
Incoming
Lets you specify the access settings for the incoming connections that use an application or a service that runs on your Mac.
Outgoing
Lets you specify the access settings for the outgoing connections that use an application or a service that runs on your Mac.
Incoming & Outgoing
Lets you configure the access settings for connections to and from the IP addresses that you specify.
This tab appears only when you select Zones in the View menu.
Use the Action pop-up menu at the bottom of the Connection Blocking window to specify other connection blocking preferences. Your options are:
Logging and notification settings
Lets you specify the type of access attempts for which your Norton product must maintain records.
You can also specify the type of access attempts about which your Norton product must notify you.
Advanced settings
Lets you specify the advanced firewall options.
Reset to defaults
Lets you reset configuration to default level.
Click Done.