if i have more than one i.e, vswitch0, vswitch1 and vswitch2.
where can i set the promiscuous mode security to accept.
will it be on the managment vswitch0 only or on all of the vswitch?
You will have to allow promiscuous mode on all port groups on the outer (native) ESXi host to which the inner (nested) ESXi VM is connected.
André