Good morning rdefino,
To see non dhcp subnets, you need to deploy RDS en every subnet with this characteristics.
What kind of network topology do you have?
I think it's something along the lines of...
Routed LAN/WAN - in which case it's an RDS in each subnet
Local LAN with subnets - RDS on a machine with a subnet mask that can see all subnets in question.
Local LAN with subnets & VLANs - RDS in each VLAN
Let me ask this. If I install it on a DHCP server, am I only seeing the systems on the subnet that the dhcp server is ip's on. Or do I see all the subnets that that DHCP server hosts.
As long as you have "DHCP monitoring" enabled in the Rogue System Detection policy the sensor on the DHCP server should report on all clients that send DHCP requests to it.
It seems to work ok in my environment, allthough i have not actually "counted the clients" to verify that it get them all yet :-)