Multiple leases

Simon Hobson dhcp at
Tue May 30 07:06:02 UTC 2006

Eustace, Glen wrote:
>We have a number of laboratories with Mac computers, all Tiger I
>We have an issue where the Macs seem to consume multiple leases during
>their boot process and the IP number they end up with doesn't always
>make it into the DNS for some reason.  This is proving to be a head-ache
>for those trying to manage the environment as often the DNS name does
>not resolve to the correct (currently allocated) lease. There is no
>shortage of leases in these networks. I have a similar situation in our
>PC labs where a PXE boot consumes a different lease from the normal
>Windows boot that follows <30 secs later.

The PXE/Windows one is a known issue, and I suspect the Macs are the same.

How are the Macs booted ?
What are their network settings ?

Specifically, you are looking for a situation where the system takes 
a lease without specifying a client-id (as happens with PXE), and 
then later takes another lease WITH a client-id (as happens with 
Windows). The server uses Client-ID as the primary key, and only uses 
MAC address if no Client-ID is supplied - therefore, if the client-id 
changes (or changes between present and not-present) then as far as 
the server is concerned it is a different client and will be given a 
different lease.

There is/was a patch floating around to modify the server behaviour - 
and at one time talk of a config option. I don't know what the 
current situation is with that.


More information about the dhcp-users mailing list