I tether my mac to my iPhone regularly and find it works well. However there is (obviously) a limited amount of bandwidth availible and I've got things like 'OS X's update service, dropbox, evernote, and a variety of other things are clamouring for a chunk of the bandwidth. Is there a handy (terminal is fine) way of saying;

'right now, only Firefox gets to use the WiFi?'

  • I have the same question. Did you try the apps suggested or find anything better?
    – Himanshu P
    Sep 11, 2014 at 17:36

2 Answers 2


You might be interested in TCPblock app.


TCPBlock is a lightweight and fast application firewall for Mac OS X 10.6 or later developed by delantis.com. The Mac OS X firewall protects you from connections that come from outside of your computer. But what about the software from your computer that opens new connections to the internet? With TCPBlock you can prevent selected applications on your computer from opening connections to the network. TCPBlock is implemented as a loadable kernel module which contains all the blocking logic. You can configure it in the System Preferences TCPBlock preference pane or with the tcpblock command line utility. All the configuration changes are made persistent in a configuration file on the hard disk. At system boot time the TCPBlock kernel extension reads its configuration from disk and is ready to go.

  • It's not working in El Capitan with SIP enabled. If you disable SIP, it may work. Oct 4, 2016 at 11:29

Little Snitch can block individual apps from making connections. It supports different profiles for different networks, so you can allow all apps through on most networks, but disable many of them when tethering.

  • 29 euros for something that should be achievable for free
    – geotheory
    Feb 16, 2015 at 9:07

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