Please have a look at this: http://www.intel.com/content/www/us/en/support/software/manageability-products/000007129.html
The problem arises if you work in a production environment where you set up completely new systems. Start condition is: - MAC addresses programmed - System UUID not yet programmed or set to e.g. 0000-0000-..... (same on all systems) Now imagine, you have some dozens of systems that simultaneously PXE-boot to get their system UUID assigned and programmed by the central server and the systems are all identified by their UUID instead of the MAC. This results in all systems getting the same IP from the DHCP server and therefor stops your production. We ran into that problem and had to update the option ROM because of that. mit freundlichen Grüßen with kind regards i. A. Dipl.Ing. (FH) Frank Hummel Systementwicklung System development ads-tec GmbH Heinrich-Hertz Str. 1 72622 Nürtingen Germany Tel.: +49 7022 2522-2412 Fax: +49 7022 2522-400 E-Mail: f.hum...@ads-tec.de Web: www.ads-tec.de -----Ursprüngliche Nachricht----- Von: ipxe-devel-boun...@lists.ipxe.org [mailto:ipxe-devel-boun...@lists.ipxe.org] Im Auftrag von Michael Brown Gesendet: Dienstag, 12. April 2016 23:19 An: Maule Mark; ipxe-devel@lists.ipxe.org; Wissam Shoukair Betreff: Re: [ipxe-devel] custom dhcp client_id option On 12/04/16 17:08, Maule Mark wrote: > Yea, they use client-identifier a lot, but I don't see that they ever > say what the id should be, only that it is unique on the subnet. > Since in the general case a system might want to have independent > ipaddr's from the same subnet assigned to dhcp clients running > per-port, wouldn't that mean we need in general for the client id to > be unique per port (with the ability to override in special case instances)? Some DHCP identifiers are intended to be unique to the machine, rather than unique to the network interface. It's unclear (to me) which is intended by the RFC. > On a separate note, is it even required that the client identifier for > the purposes of address assignment come from DHCP option 61? The pxe > spec seems to use the ambiguous "DHCP option tags" terminology, > implying that maybe it is the dhcp server that should be configurable. Section 2.3 (page 21) of the PXE spec states: The Client UUID field specifies a universally unique ID (UUID), retrieved from the client system. The client must have a UUID and must report it in tag #97 and #61. so the PXE spec does require that we put the (SMBIOS) UUID into DHCP option 61. There's nothing in the PXE spec that requires the DHCP server to use option 61 for the purposes of address assignment, however. Michael _______________________________________________ ipxe-devel mailing list ipxe-devel@lists.ipxe.org https://lists.ipxe.org/mailman/listinfo.cgi/ipxe-devel _______________________________________________ ads-tec GmbH Sitz: 72622 Nürtingen Registergericht Stuttgart HRB 224527 Geschaeftsfuehrer: Dipl.-Ing. Thomas Speidel _______________________________________________ Diese E-Mail enthaelt vertrauliche und/oder rechtlich geschuetzte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtuemlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese E-Mail. Das unerlaubte Kopieren, jegliche anderweitige Verwendung sowie die unbefugte Weitergabe dieser Mail sind nicht gestattet. _______________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure, distribution or other use of the material or parts thereof are strictly forbidden. _______________________________________________ _______________________________________________ ipxe-devel mailing list ipxe-devel@lists.ipxe.org https://lists.ipxe.org/mailman/listinfo.cgi/ipxe-devel
