Editing Preboot Execution Environment (section)

== Sibling environments ==
[[Apple Inc.|Apple]] has come up with a very similar network boot approach under the umbrella of the [[Boot Service Discovery Protocol|Boot Server Discovery Protocol]] (BSDP) specification. BSDP v0.1 was initially published by Apple in August 1999<ref name="BSDP_1">{{cite web
 | url = http://opensource.apple.com/source/bootp/bootp-170/Documentation/BSDP.doc
 | title = NetBoot 2.0: Boot Server Discovery Protocol (BSDP) v0.1
 | publisher = Apple Corporation
 | format= Doc
 | date = 2003-12-02
 | access-date = 2014-04-04
}}</ref> and its last v1.0.8 was published in September 2010.<ref name="BSDP_2">{{cite web
 | url = https://opensource.apple.com/source/bootp/bootp-254.1/Documentation/BSDP.doc
 | title = NetBoot 2.0: Boot Server Discovery Protocol (BSDP) v1.08
 | publisher = Apple Corporation
 | format= Doc
 | date = 2010-09-17
 | access-date = 2014-04-04
}}</ref> [[Mac OS X Server]] included a system tool called [[NetBoot]]. A NetBoot client uses BSDP to dynamically acquire resources that enable it to boot a suitable operating system. BSDP is crafted on top of DHCP using vendor-specific information to provide the additional NetBoot functionality not present in standard DHCP. The protocol is implemented in client firmware. At boot time, the client obtains an IP address via DHCP then discovers boot servers using BSDP. Each BSDP server responds with boot information consisting of:
* A list of bootable operating system images
* The default operating system image
* The client's currently selected operating system image (if defined)

The client chooses an operating system from the list and sends a message to the server indicating its selection. The selected boot server responds supplying the boot file and
boot image, and any other information needed to download and execute the selected operating system.