Stop DHCP between two LAN ports in cyberoam

Question

I have two subnets each subnet connected to one Cyberoam port as LAN. 
 PortA with subnet LAN1 192.168.1.0/24 and DHCP server = Windows 2012 
 PortC with subnet LAN2 192.168.100.0/24 DHCP server = Cyberoam 
 each port connected to separate Switch with no connection between them, But the problem the devices from LAN1 take IP from LAN2 DHCP server and LAN2 take IP from LAN1 DHCP server. 
 I need to prevent any device from LAN1 to take IP from LAN2 and same with LAN2. 
 I contact Cyberoam Support but they can't fix

sachingurung · Accepted Answer

Hi Saleem, 
 In the DHCP Server configuration on Cyberoam, did you select LAN2 as Interface in the DHCP configuration? If set to NONE then Cyberoam will listen to DHCP broadcast from any interface and such issues can occur. 
 Thanks,

Saleem Nasser · Answer

I was found the problem, It was from our network. Someone connect network cable between LAN1 and LAN2 switches.