In the article, Wolf said, “one significant issue with virtual machine security is with virtual switch isolation. The current all-or-nothing approach to making a virtual switch ‘promiscuous’ in order to connect it to an IDS/IPS is not favorable to security.”
For example, “if you connect an IDS appliance to a virtual switch in promiscuous mode,” Wolf said, “not only can the IDS capture all of the traffic traversing the switch, but every other VM on the same virtual switch in promiscuous mode could capture each other’s traffic as well.”
This statement ruffled some feathers at VMware, and they quickly emailed me and Burton to “educate us” and the VMware community that in fact, VMware allows (and encourages) users to configure only the ports they need to be promiscuous as such. This is not a per vswitch setting, but rather a per portgroup setting. The way to configure a vswitch for IDS/IPS is to create a separate portgroup from those used for normal VMs and configure it for “Promiscuous Allowed,” a VMware spokesperson said.
After testing this out in his own lab, Wolf said it is really an easy solution, because the architecture is already there.