SV: DISCOVER bursts

[Lars Jacobsen]

Well I read the question as regardless of the CPE "misbehaver" (asking for
an IP address 4 times) the server should NEVER offer more than max two
addresses to a client in this particular config. But it does, why ?

I expect Staffan has:
spawn with option agent.circuit-id;
lease limit 2;
somewhere in his config.

Maybe as suggested an race/timing issue inside the server, keeping track on
offered not yet acknowledged leases, compared to some of the rules for this
specific client.


/Lars



> -----Oprindelig meddelelse-----
> Fra: dhcp-users-bounce at isc.org [mailto:dhcp-users-bounce at isc.org] På vegne
> af Milton W. Schober, Jr.
> Sendt: 5. januar 2007 15:56
> Til: dhcp-users at isc.org
> Emne: Re: DISCOVER bursts
> 
> What is the CPE?  We have seen something similar with Thomson IPTV set top
> boxes, but the problem is in the STB, not the server.
> 
> Milton Schober
> ----- Original Message -----
> From: <Staffan.Ungsgard at teliasonera.com>
> To: <dhcp-users at isc.org>
> Sent: Friday, January 05, 2007 3:55 AM
> Subject: DISCOVER bursts
> 
> 
> > Hi
> > We have problem with a special customers CPE, where the CPE send four
> > rapid DHCPDISCOVERS with just 20 milliseconds apart.
> > When the DHCP server gets the DISCOVERS it issues different addresses on
> > each discover. I have snoop logs of the traffic, and the DISCOVERS are
> > indeed exactly the same in each DHCPDISCOVER. It seems that the when the
> > server handles the second DISCOVER, it doesn't "remeber" that is has
> > already offered a fresh ip address from an identical DHCPDISCOVER 20 ms
> > earlier.
> > To furthermore illustrate this, we have a lease limit of two, so
> > technically it shouldn't offer more than two addresses to the same line
> > identifier even if the "Client Identifier" differed, but it isses three
> > different addresses and only barfs at the fourth DHCPDISCOVER saying "no
> > billing".
> >
> > Is there a race problem in the dhcp server ?
> >
> > The hardware is a Sun V210 running Solaris 8. No supermachine, but
> they're
> > still selling them.
> >
> > Best Regards
> >
> > -- Staffan Ungsgard
> >
> >
> >
> >
> >
> >
> >
> > --
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > Version: 7.1.410 / Virus Database: 268.16.5/616 - Release Date: 1/4/2007
> >
> >
> 
> 
> 
> 
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.410 / Virus Database: 268.16.6/617 - Release Date: 05-01-2007
> 11:11