For testing purposes (testing raw network speed over a number of cables) i have equippped my Mac Book pro with a Thunderbolt to Gigabit Ethernet Adapter besides the built-in gigabit ethernet connection.

Both interfaces have been assigned a manual IP in the 10.0.*/24 range.

Starting iperf with iperf -s 10.0.0.1, then starting the client with iperf -c 10.0.0.1 yields speeds of over 40 Gigabit per second. I assume (correctly so according to some googling) that not the interface itself is used but rather the local loopback interface as both IPs reside on the same computer. So my thought was to disable lo0, even just temporarily by issuing sudo ifconfig lo0 down. Thies doesn't work (it might have worked once for a few seconds but I can't prove that). lo0 just stays up.

Is there a way to (temporarily) disable the local loopback interface lo0 so I can do my tests?

Thanks!

For testing purposes (testing raw network speed over a number of cables) i have equippped my Mac Book pro with a Thunderbolt to Gigabit Ethernet Adapter besides the built-in gigabit ethernet connection.

Both interfaces have been assigned a manual IP in the 10.0.*/24 range.

Starting iperf with iperf -s --bind 10.0.0.1, then starting the client with iperf -c 10.0.0.1 yields speeds of over 40 Gigabit per second. I assume (correctly so according to some googling) that not the interface itself is used but rather the local loopback interface as both IPs reside on the same computer. So my thought was to disable lo0, even just temporarily by issuing sudo ifconfig lo0 down. Thies doesn't work (it might have worked once for a few seconds but I can't prove that). lo0 just stays up.

Is there a way to (temporarily) disable the local loopback interface lo0 so I can do my tests?

Thanks!