How the Remote Installation Boot Disk Works

This article describes how the remote installation boot disk works.

The remote installation boot disk allows the Remote Installation Services (RIS) server to be used by clients that do not have a PXE-enabled network adapter. The boot disk creates a Pre-Boot Execution Environment (PXE) emulator that works on supported PCI network adapters that allow them to connect to the RIS server. Because one disk works for all network adapters, a specific network boot disk is no longer required. The supported network adapters are listed in the utility that creates the boot disk. This utility is named Rbfg.exe. You can find Rbfg.exe in the Reminst\Admin\I386 network folder.

The remote installation boot disk is useful if you need to use RIS to install programs to a portable computer, for example a laptop computer. You can place the laptop computer in a docking station and use an RBFG-generated boot disk to connect to the server, provided that the docking station contains a supported PCI network adapter.

Network Adapter Issues

RBFG floppy disks support only the adapters in the following list. All of the adapters in this list are PCI-based adapters. Network adapters that are ISA-, ISA(PnP)-, or PCMCIA-based are not supported. The network adapters that are supported are:

3Com Network Adapters

• 3c900 (Combo and TP0)
• 3c900B (Combo, FL, TPC, TP0)
• 3c905 (T4 and TX)
• 3c905B (Combo, TX, FX)

AMD Network Adapters

• AMD PCNet and Fast PC Net

Compaq Network Adapters

• Netflex 100 (NetIntelligent II)
• Netflex 110 (NetIntelligent III)

Digital Equipment Corporation (DEC) Network Adapters

• DE 450
• DE 500

Hewlett-Packard Network Adapters

• HP DeskDirect 10/100 TX

Intel Corporation Network Adapters

• Intel Pro 10+
• Intel Pro 100+
• Intel Pro 100B (including the E100 series)

SMC Network Adapters

• SMC 8432
• SMC 9332
• SMC 9432

You cannot add additional network adapters to the RIS boot disk. Microsoft adds additional network adapters from time to time and makes the updates in the Rbfg.exe tool available through normal distribution channels, such as the Web, Windows Update, and future service pack or feature pack updates.

GUID Issues

When a PXE client connects to the server, one of the items that is exchanged before a logon screen appears is the globally unique identifier (GUID) of the computer. The GUID a 128-bit integer (16 bytes) has a very low probability of being duplicated. The GUID is stored with the computer account object that is created in Active Directory. Network adapters that do not have a PXE boot ROM do not have a GUID so Boot Information Negotiation Layer (BINL) uses the Media Access Control (MAC) address (a number that is unique on that particular network at that particular time) to create a GUID. This means that the newly created computer account object is actually associated with the network adapter, not with the computer.

If you move the network adapter to another computer, RIS interprets the new computer as the old computer. The administrator must delete the GUID from the computer account object for the old computer. If a user tries to install the new computer under a different computer name, a duplicate GUID warning displays the names of the computers on the network that already have the same GUID. Relationships of GUIDs to computer account objects ought to be one-to-one.