# ovs-vsctl add-port br-ex INTERFACE_NAME is crashing my VM

So, I'm new, so thank you in advance for your insight and patience.

I'm working through the following install guide: http://docs.openstack.org/juno/install-guide/install/apt/content/ (http://docs.openstack.org/juno/instal...) on VMware Fusion 7. I am stuck on section 6. Add a networking component, specifically on installing and configuring the network node. I have 4 NIC's on my network node: eth0 is shared connection with my mac, eth1 is the hostonly management network, eth2 is the hostonly tunnel network, and eth3 is the external network with unassigned IP.

When I run # ovs-vsctl add-port br-ex eth3, my VM crashes, and I have to reboot my entire system.

I have successfully walked through the install guide up to this point. Any thoughts on the issue? Where to begin troubleshooting?