Ethernet Interface Bonding

I am trying to bond two Apple USB Ethernet adapters into a single network device that I can use to monitor network traffic coming from a passive network tap (one interface for each monitor port on the tap).

I can confirm that each of the interfaces are seeing the expected network traffic when I use tcpdump so I know that they are both working as expected.

I have tried to use the network preferences to add an aggregate interface and assign each of the adapters, which shows the interface appropriately configured but still results in the same problem I am experiencing now.

I have also tried to manually configure the bond using the "ifconfig bond0 bonddev".

Both ways result in a bonded interface being created, but none of the traffic from either en2 or en3 being redirected to this new interface.

Is there something I'm missing here?

Thanks

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