Look, a DHCP server will serve by default only the computers from the same LAN segment and same IP class.
170.190.240.x it is not in the same IP class.
The computers you want to serve are in the same LAN segment?
DCHP works on broadcast. The clients can't broadcast in another LAN segment unless there is a bootp relay agent on the router to forward dchp requests to another LAN segment.
Do you understand what I'm saying?