DHCP gives out same IP address to two clients

sthaug at nethelp.no sthaug at nethelp.no
Thu Jan 9 14:32:18 UTC 2014

> I'm not sure what could be happening here, but it looks like one of our
> DHCP servers for some reason decides to give out the same IP address to
> two clients. The version is 4.2.5-P1.
> The thing that strikes me as perhaps a bit odd is that the hardware
> addresses of the two clients are _almost_ the same (one ends in "d9", the
> other in "db"). That might be a coincidence, though.
> Am I missing something obvious here? Or could someone point me in the
> right direction? :)

Your DHCP server is working as expected. The standard says that client
identifier should be used in preference to MAC address - if it exists.
Both your leases show client identifier (uid) "589br".

There's been multiple requests through the years to always use MAC
address and ignore client identifier - and also some patches.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no

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