Occationally we are having a problem with workstations in one location
receiving DHCP IP address from a DHCP server at another location over our

For example, workstation is on 192.168.1.x network. DHCP server is on
that subnet. Remote WAN server with DHCP is on 192.168.5.x.
Occationally, the workstation on 192.168.1.x is receiving a 192.168.5.x
address. After a reboot, all is well.

Is there any way to contain DHCP requests to the same subnet as the
requesting workstation ?