Two different IP addresses leased out to the same device

Markus Zuercher zuerchermarkus at
Thu Sep 10 06:45:14 UTC 2009

Hi Simon,

> This is a longstanding issue when a machine boots with multiple DHCP clients
> - and it's mostly down to Microsoft that the problem exists. The RFC doesn't
> specify what should be in the Client-ID, and Microsoft decided that putting
> the MAC address in there made sense. This isn't wrong, just different to
> everyone else who default to not supplying a Client-ID at all.

Hmm, If I understand you correct, the client's PXE client first
acquired an IP address, supplied a Client-ID and then Windows did the
same thing without a Client-ID? I think it would help to not save the
Client-ID in the lease database - is this correct?

> A proposed feature that I believe never made it was to allow the
> administrator to configure the database key - it currently defaults to
> "pick-first(client-id, hardware)". If changed to just plain "hardware" then
> Client-ID would be ignored.

Looks like this is in the program code, right? Is there anything I can
do in my server config to get the same effect?

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