@pilgrimage This problem is connected to your other post: https://forums.fogproject.org/topic/17255/about-dhcp-and-pxe-problem?_=1707994213348
Your issue is infrastructure and not a fog specific issue. DHCP works based on broadcast messages. These broadcast messages typically are not passed between subnets. On your subnet router there is a service that can be turned on to relay dhcp communications between subnets. I would also think this service is configured on your network because you have client computers on one subnet and servers on another.
Since you are using dnsmasq to provide the pxe boot information since your dhcp server can’t be changed, you need to update this dhcp-helper / dhcp relay agent on your network router to include your dnsmasq server in the list of dhcp servers this service notifies of a dhcp request. Once that is done your dnsmasq server will hear the dhcp request from the remote subnet and respond with the pxe boot information.