Well I've started migrating our environment from ESX 3.5 to vSphre 4. Management has requested that we take a look at VMware View which is not fully compatible with vSphere yet. So In my brilliant thinking I thought it'd be pretty nifty to setup a small ESX 3.5 environment in our vSphere cluster. The vCenter server is complete and ESX 3.5 installed fine boots up and everything works great except I cannot access it via the network. I'm using the standard e1000 driver for it as well. If anyone could shine a light on this I would appreciate it.
You probably need to configure your virtual switch to allow promiscuous mode
That is what did it! Now next question why would that make a difference? I have a theory but not 100% sure with it.
Remember that vSwitch are similar as a bridge connection.
And they need to "listen" all the traffic to define the network topology.