[ipxe-devel] gPXE 1.0.1 Boot Server Discovery behaviour

carlyoung at keycomm.co.uk carlyoung at keycomm.co.uk
Wed Nov 10 17:19:11 UTC 2010

Hi all,

I have a question about the standard behaviour of gPXE 1.0.1 and iPXE. (The tests I did were using VMware E1000 based boot-rom)

the PXE 2.1 spec states [in para. 2.4.4] that the client should provide option 71 (PXE_BOOT_ITEM)  in boot server discovery but I cannot see this in a trace using the gPXE 1.0.1 boot rom.

I have a trace when using a CA MPC boot server (all I have access to currently). The extended DHCP offer from the boot server has option/sub-option 43/8 and 43/9 (PXE_BOOT_SERVERS and PXE_BOOT_MENU respectively) and these both have the boot-server type (0007) present.

The client then sends a DHCPREQUEST boot server discovery request without the PXE_BOOT_ITEM type and the CA server ignores this request as the explicit boot server type has not been specified.

Table 2.1 states that the PXE_BOOT_ITEM (71) type is required (not optional) and has note #6:

This option is required to discover Boot Servers. Only the client may change the type field; either the
client or the server may change the layer field. Layer 0 always indicates the first boot file for a
particular Boot Server type. Boot Servers capable of providing the boot file requested in the
PXE_BOOT_ITEM must respond. Boot Servers not capable of providing the boot file requested
must not respond.

As far as I can tell then, the CA boot-server is behaving correctly. Am I understanding this correctly or not?

Thanks for any advice, regards,


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