The Requerydhcp-Options Keyword - Neoware e140 - Thin Client User Manual

The ReQueryDHCP-
Options Keyword
Syntax:
ReQueryDHCPOptions = <D || N || I>
Examples:
ReQueryDHCPOptions = Discover
ReQueryDHCPOptions = None
ReQueryDHCPOptions = Inform
Default value:
ReQueryDHCPOptions = I
Warning: This option implements a work around for a few and
limited number of technical issues related to very specific DHCP
implementations. It should only be used when such a case has been
clearly and unambiguously identified.
Before booting from the image, mPXELoader has to re-issue a query
to the DHCP server in order to ensure it gets all the DHCP options
that have been set (in the DHCP configuration) for the booting
station. The reason this is required is because the PXE firmware only
queries a limited set of DHCP options, and a few options that
Windows needs do not belong to this set.
The regular way of accomplishing this is through the use of a
DHCPINFORM DHCP request, and this is what mPXELoader uses.
But it appears that certain versions/revisions of some DHCP servers
do not process the DHCPINFORM request in a conformant way,
resulting under certain circumstances in incorrect, empty or missing
DHCP values in the client.
This keyword accepts three values, D, N and I. "I" is the default.
If set to D, mPXELoader will use an alternate method, DHCPDIS-
COVER, to request the option parameters from the DHCP server.
This use of the DHCPDISCOVER slightly streches the interpreta-
tion of the DHCP specifications, but usually works and can be tried
as an alternative method to the regular DHCPINFORM method.
Note that versions of mPXELdr prior to the one shipped with Image
Manager v4.6.0 (and all versions of PXEOSLDR.bin) were using
DHCPDISCOVER.
If set to N, mPXELoader will not do any kind of DHCP requery and
will simply pass to the booting OS the options subset that the DHCP
The mPXELdr Configuration File
Keywords 267