ESXi, FreeNAS, Jails

This is a quick tip for anyone running FreeNAS on ESXi who also use jails.

I use Crashplan on my FreeNAS box for backups. It’s brilliant because it’s easy, not super expensive, and usually well integrated. On my new FreeNAS box, however, my jails were having some network issues. Specifically, they could not get a DHCP lease or ping anything, like so:

As it turns out, you need to have Promiscuous Mode enabled for the vSwitch used by the FreeNAS server. Once I turned it on, my Crashplan jail immediately came to life.