"Healthy" servers issuing leases for length of MCLT

[Glenn Satchell]

On 07/13/10 05:25, Oscar Ricardo Silva wrote:
> On 07/10/2010 07:00 AM, dhcp-users-request at lists.isc.org wrote:
>> Message: 3
>> Date: Fri, 09 Jul 2010 19:36:57 -0500
>> From: Oscar Ricardo Silva<oscars at mail.utexas.edu>
>> Subject: "Healthy" servers issuing leases for length of MCLT
>> To:dhcp-users at lists.isc.org
>> Message-ID:<4C37C0A9.6070903 at mail.utexas.edu>
>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>
>> We have a pair of servers running in failover mode and they appear to be
>> healthy and communicating with each other. The problem is that while we
>> have the lease time set to 7 days, leases are only handed out for the
>> length of the MCLT. I understand this is the expected behavior when the
>> pair of servers are not communicating but these servers are in a normal
>> state.
>>
>> And yes, I know the split statement is set to 255 but we do this to
>> force preference onto the primary server. We have two other failover
>> pairs running in the same manner without problem.
>>
>> I've verified that there are no crazy time differences between the two.
>> I've also restarted one server at a time and waited for them to
>> re-establish communication.
>>
>> Any thoughts on why leases for the length of the MCLT are being handed
>> out on a supposedly healthy pair of servers?
>>
>>
>>
>> Oscar
>
>
> I should add that I understand the initial lease may only be handed out
> for the length of the MCLT. The problem is that even after several days,
> the device (Cisco Wireless Access Points 1242s and 1142s) retain the
> lease for ONLY the MCLT. The default lease times never goes into effect.
> This isn't restricted to one specific device .
>
>
> Oscar

Does this behaviour only hold for the Cisco WAPs on your network, or do 
all clients (printers, PCs, etc) behave this way?

I suggest that you set up a packet capture using, for example, tcpdump, 
snoop, wireshark, etc, then do a renewal on the client and see what 
lease length is set in the packets on the wire. At least this way you 
can determine if it is the server or the client. It may be that these 
particular clients will only request a lease time equal to the one it 
was first issued with, perhaps?

-- 
regards,
-glenn