OSX Link Aggregation for USB tether and WiFi?

Question

Is this kind of link aggregation even possible?

On a Windows machine, there are several 3rd-party applications which make use of bonding and load balancing multiple network interfaces for increased throughput, such as Connectify Dispatcher, for example. Would it be possible to develop such an app for OSX? Is there already any 3rd-party software which does this on OSX? The closest thing I could find was IPNetRouterX, which I've failed to use for bonding USB and WiFi network interfaces.

I have also tried the following line in OSX's terminal:

sudo networksetup -createBond bond0 en1 en3

...where en1 is my WiFi interface and en3 is my USB network interface, which simply results in:

** Error: The parameters were not valid.

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Likely, there would need to be some sort of Layer 2 "magic glue" to make this in any way a possibility... but primarily being a Windows programmer, I'm not sure if Apple would enjoy allowing that level of programming access, considering how proprietary they like to be...

Any idea what can be done here?

Answer 1

There are options to networksetup to tell you whether the OS can bond a particular port or not. To do so, you need to hand it a "hardware port", which you can find by using:

networksetup -listallhardwareports

Each of those, in turn, can be queried using

networksetup -isbondsupported <HW Port Name>

Bonded networks are set up using the networksetup port name, not the kernel interface name, so if you were to bond two ethernet networks, you would do so like this:

networksetup -createBond myBondedNet 'Ethernet 1' 'Ethernet 2'

Querying the ports on my 2009 MacPro running 10.9, I find only the hardware ethernet ports to respond YES to the -isbondsupported inquiry.

Note that I didn't have to have the port operational in order for -isbondsupported to return YES, so in my case both of my ethernets responded YES even though only one is currently connected.