same ip to the same mac ?
Petre Bandac
petre at kgb.ro
Thu Feb 1 12:39:59 UTC 2007
On Thu, 1 Feb 2007 08:15:55 +0000 Anno Domini, the honourable Simon
Hobson wrote using one of his keyboards:
> Petre Bandac wrote:
>
> >while parsing my dhcpd logs, I have noticed a strange thing:
> >apparently, the same ip gets somehow "reserved" for the same mac
> >address
> >
> >thus, the client always gets the same ip everytime it connects
> >(which I want to prevent)
>
> Yes this is the design of the ISC server and is (IIRC) required by
> the RFC. Certain other servers are non compliant in this area (along
> with a few others).
>
> It is why you will find lease entries in the leases file for expired
> leases, so the server can keep track of what leases it has given out
> in the past.
>
> The algorithm for choosing a lease for a client is (roughly) :
>
> Has this client had a lease in it's current subnet before ?
> If so, then give it the last address it had
>
> Is there an unused address ?
> If so then allocate a previously unused address
>
> Find a previously used but currently free address and offer that.
> This is done on a least recently used basis, and obviously once the
> address has been reused like this then the link with it's previous
> usage is lost.
>
>
> Now, why do you want the address to keep changing ?
>
good question
the network is in a small residential area, and I would like the ip to
be as "dynamic" as possible
guess I shall keep it the way it is now
thank you for your answers,
petre
--
Petre Bandac
Network Scientist
-
petre at kgb.ro
More information about the dhcp-users
mailing list