Depending on the router models in use, the specific router configuration of DHCP broadcast forwarding may be supported to either a subnet (or router interface) or a specific host. If the DHCP servers and the computer running Windows Deployment Services are separate computers, ensure that the routers that forward DHCP broadcasts are designed so that both the DHCP and Windows Deployment Services servers receive the client broadcasts; otherwise, the client computer does not receive a reply to its remote boot request.
Is there a router between the client computer and the remote installation server that is not allowing the DHCP-based requests or responses through? When the Windows Deployment Services client computer and the Windows Deployment Services server are on separate subnets, configure the router between the two systems to forward DHCP packets to the Windows Deployment Services server. This arrangement is necessary, because Windows Deployment Services client computers discover a Windows Deployment Services server by using a DHCP broadcast message. Without DHCP forwarding set up on a router, the client computers’ DHCP broadcasts do not reach the Windows Deployment Services server. This DHCP forwarding process is sometimes referred to as DHCP Proxy or IP Helper Address in router configuration manuals. Refer to the router instructions for more information about setting up DHCP forwarding on a specific router.