SCCM PXE

=SCCM - PXE - gPXE=

Some notes from watching with wireshark

Booting via a USB stick with gPXE !

Emulating a normal PXE boot
...on a correctly booting subnet, with SCCM setup and a machine configured within it.

dhcp net0 set next-server XXX.XXX.32.60 chain smsboot\x64\wdsnbp.com
 * 1) !gpxe

Goes through and works( this emulates a standard PXE boot)

Direct chain boot to pxeboot.com, using just next server
This bypasses wdsnbp.com checks.

dhcp net0 set next-server XXX.XXX.32.60 chain smsboot\x64\pxeboot.com (or pxeboot.n12)
 * 1) !gpxe

What happens;

\smsboot\x64\pxeboot.com \smsboot\x64\bootmgr.exe \Boot\Fonts\wgl4_boot.ttf (not found) \smsboot\x64\boot.ini (not found) \Boot\BCD (not found) \Boot\Fonts\wgl4_boot.ttf (not found) = FAIL

Direct chain boot to pxeboot.com using just next server, specifying DHCP options 243 and 252
243 & 252 are options set from what wdsnbp.com discovers, they are set before pxeboot.com is requested.

dhcp net0 set 243:string SMSTemp\2012.02.20.10.46.19.0003.{99FE0226-0DBD-45BF-8CF0-028422086DF8}.boot.var set 252:string SMSTemp\2012.02.20.10.46.18.06.{99FE0226-0DBD-45BF-8CF0-028422086DF8}.boot.bcd set next-server XXX.XXX.32.60 chain smsboot\x64\pxeboot.com
 * 1) !gpxe

The flow with wireshark...

\smsboot\x64\pxeboot.com \smsboot\x64\bootmgr.exe \Boot\Fonts\wgl4_boot.ttf (not found) \SMSTemp\2012.02.20.10.46.18.06.{99FE0226-0DBD-45BF-8CF0-028422086DF8}.boot.bcd (fail) -no blocksize set? \SMSTemp\2012.02.20.10.46.18.06.{99FE0226-0DBD-45BF-8CF0-028422086DF8}.boot.bcd \Boot\Fonts\wgl4_boot.ttf (not found) \hiberfil.sys (not found) \SMSImages\SMSPKG\UL100006\boot.UL100006.wim (fail) -no blocksize set? \SMSBoot\boot.sdi (fail) -no blocksize set? \SMSBoot\boot.sdi \SMSImages\SMSPKG\UL100006\boot.UL100006.wim \Boot\Fonts\wgl4_boot.ttf (not found) \SMSTemp\2012.02.20.10.46.19.0003.{99FE0226-0DBD-45BF-8CF0-028422086DF8}.boot.var

TFTP server seems to not like unspecified block sizes. This works as far as the client trying to find the SMS/variables.dat file, which it tries to pull via a util SMSTFTP and fails.