- I suppose so, that managed nework can have a different IP network from each machine, as each one have her own phisical nic?
Yes, the uplink to a physical switch is comparable to a trunk between physical switches and all VMKernel port groups as well as the virtual machines are connected to the virtual switch using their own unique IP address. With different IP subnets on the ESXi host, you may need to properly configure the uplink port (i.e. 802.1Q).
- And, what is the 'promiscuous' option of each vnic and each vswitch ?
With promiscuous mode disabled, network traffic is only sent to the port group on which the target MAC address is directly registered. With promiscuous mode enabled traffic will be sent to the port group(s) regardless. This is required for e.g. a nested ESXi host where the VM's are connected to the nested host's vSwitch/port groups rather than to the outer ESXi host's port groups directly.
André