Your network consists of a single Active Directory site that includes two network segments. The
network segments connect by using a router that is RFC 1542 compliant. You plan to use Windows
Deployment Services (WDS) to deploy Windows Server 2008 R2 servers. All new servers support
PreBoot Execution Environment (PXE). You need to design a deployment strategy to meet the
following requirements:
Support Windows Server?2008 R2
Deploy the servers by using WDS in both network segments
Minimize the number of servers used to support WDS
What should you include in your design?

A.
Deploy one server. Install WDS and DHCP on the server. Configure the IP Helper tables on the
route between the network segments.

B.
Deploy two servers. Install WDS and DHCP on both servers. Place one server on each of the
network segments. Configure both servers to support DHCP option 60.

C.
Deploy two servers. Install WDS and DHCP on both servers. Place one server on each of the
network segments. Configure both servers to support DHCP option 252.

D.
Deploy two servers. Install WDS and DHCP on one server. Install DHCP on the other server. Place
one server on each of the network segments. Configure both servers to support DHCP option 60.

Explanation:

http ://support.microsoft.com/kb/926172
IP Helper table updates
The PXE network boot method uses DHCP packets for communication. The DHCP packets serve a
dual purpose. They are intended to help the client in obtaining an IP address lease from a DHCP
server and to locate a valid network boot server. If the booting client, the DHCP server, and the

network boot server are all located on the same network segment, usually no additional
configuration is necessary. The DHCP broadcasts from the client reach both the DHCP server and the
network boot server.
However, if either the DHCP server or the network boot server are on a different network segment
than the client, or if they are on the same network segment but the network is controlled by a
switch or a router, you may have to update the routing tables for the networking equipment in order
to make sure that DHCP traffic is directed correctly.
Such a process is known as performing IP Helper table updates. When you perform this process, you
must configure the networking equipment so that all DHCP broadcasts from the client computer are
directed to both a valid DHCP server and to a valid network boot server.
Note: It is inefficient to rebroadcast the DHCP packets onto other network segments. It is best to
only forward the DHCP packets to the recipients that are listed in the IP Helper table.
After the client computer has obtained an IP address, it contacts the network boot server directly in
order to obtain the name and the path of the network boot file to download. Again, this process is
handled by using DHCP packets.
Note: We recommend that you update the IP Helper tables in order to resolve scenarios in which the
client computers and the network boot server are not located on the same network segment.