PRB: Windows CE Does Not Send DHCP Option 12 (259825)


The information in this article applies to:

  • Microsoft Windows CE Operating System, Versions 3.0
  • Microsoft Windows CE Operating System, Versions 2.12
  • Microsoft Windows CE Operating System, Versions 2.11
  • Microsoft Windows CE Operating System, Versions 2.0
This article was previously published under Q259825

SYMPTOMS

When Windows CE broadcasts Dynamic Host Configuration Protocol (DHCP) DISCOVER packets on the network, it does not include DHCP option 12 - Host Name Option.

CAUSE

The Windows CE DHCP layer does not transmit this data because the machine host name may not be set to a unique name at the time the DHCP request is broadcast.

RESOLUTION

Windows CE version 2.12 with QFE updates #1 and #2 can include DHCP option codes that are retrieved from the system registry with each DHCP request packet. The option code and values must be set in the TCPIP parameters area for the interface. For example: 
[HKEY_LOCAL_MACHINE\Comm\NE20001\Parms\TcpIp\DhcpSendOptions]
@=""
"12"=hex:0c,06,47,6f,6f,62,65,72
The default value for the registry key must be set (as shown with the @= line). The value name should be the option code being requested, and the value data must include the option code, length, and associated data.

In the example, the option code is 12 (0x0c), the length is 6, and the data is the ASCII bytes for the string "Goober".

Because the GetHostName and SetHostName functions operate only on the name stored in the HKEY_LOCAL_MACHINE\Ident registry key, care must be taken to keep this DHCP registry value synchronized if the Windows CE platform allows the network name to be changed.

STATUS

This behavior is by design.
Modification Type:MajorLast Reviewed:4/15/2004
Keywords:kbprb KB259825
©2004 Microsoft Corporation. All rights reserved.