Multilple leases with same client identifier

Simon Hobson dhcp1 at
Thu Oct 25 07:15:20 UTC 2012

Christian Kratzer wrote:

>We have one specific device that sends identical ethernet addresses 
>and uid for all the requests the different vlans.
>When the device requests 3 leases one for each vlan it is on. The 
>DHCP server releases the previously assigned leases as it assumes 
>that the device has moved to a another network.

That's not default behaviour - do you have (IIRC) 
one-lease-per-client turned on ?

AFAIK it's valid to use the same MAC address and ClientID on multiple 
VLANs - if you think about it, if it is just different VLANs then the 
ethernet interface is the same (so same MAC) and there's no reason 
for the ClientID to vary.

Simon Hobson

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