Duplicate lease, different ip.

[Douglas Power]

Hi.

I have applied the patch from <http://www.cs.tau.ac.il/~didi/dhcp/> to
V3.1.0a3 and this fixes the duplicate but I am unable to start the
service through init.d as it gives me a usage error:

------------------------------------------------------------------------
Internet Systems Consortium DHCP Server V3.1.0a3
Copyright 2004-2007 Internet Systems Consortium.
All rights reserved.
Usage: dhcpd [-p <UDP port #>] [-d] [-f]
             [-cf config-file] [-lf lease-file]
                   [-tf trace-output-file]
                   [-play trace-input-file]
             [-t] [-T] [-s server] [if0 [...ifN]]

If you did not get this software from ftp.isc.org, please
get the latest from ftp.isc.org and install that before
requesting help.

If you did get this software from ftp.isc.org and have not
yet read the README, please read it before requesting help.
If you intend to request help from the dhcp-server at isc.org
mailing list, please read the section on the README about
submitting bug reports and requests for help.

Please do not under any circumstances send requests for
help directly to the authors of this software - please
send them to the appropriate mailing list as described in
the README file.
-------------------------------------------------------------------------

It works fine if I start it manually without the -chroot option which I
am not happy about as it isn't secure enough. I will let you know if I
can figure this out. If you have any suggestions they would be greatly
appreciated.

Regards,

Doug.
 


On Wed, 2007-05-02 at 14:28 -0700, David W. Hankins wrote:
> On Mon, Apr 30, 2007 at 12:11:18PM -0300, Bruce Hudson wrote:
> >     However, the first time the server see a request with an identifier it
> > will "upgrade" an existing lease for that client address that does not have
> > one by adding it. The process is not reversible so any requests there-after
> > without an idetifier are a different client. There was an ancient message
> > to the list from Ted Lemon that called this "tragically unavoidable". 
> 
> This is only true IFF you are running an older version of the software
> (with a bug) and the client that has a uid and identical chaddr has
> "requested" the old address.  New versions will never 'upgrade' a
> lease from chaddr-identified to client-identified.
> 
> That does not help someone who is using PXE because ping-before-offer
> will successfully ping the PXE client, and abandon its lease, so even
> the old software won't work.
> 
> 
> I'm not sure it's unavoidable.  But it's "working as intended" that
> these two clients get different leases.  This was Ted's interpretation
> of RFC2131, and I share it.
> 
> It's certainly tragic.
> 
> I wanted to get a feature into 3.1.0 that would help administrators
> sort client identification problems out using config syntax (with an
> eye towards the future which is RFC4361).  We cut 3.1.0 to alpha
> before I could start on that feature.
> 
> 
> I don't remember if didi wrote a second patch, but the one I
> remember disabled the client-identifier entirely...this is not
> something we feel we can incorporate in the official software.
> 
-- 
Douglas Power <dpower at fnb.co.za>
FNB

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