Re: Getting Peer hold all free leases

I have not figured out any cause.  But it has been happening somewhat
randomly for years.  I did not open a case with ISC, so partly my fault.
With the work on Kea, I don't know if they would have time to fix DHCPD
at this point.

-- 
Bob Harold
DNS and DHCP Hostmaster - UMNet
Information and Technology Services (ITS)
[email protected]


On Tue, Aug 17, 2021 at 12:11 PM Kraishak Mahtha <[email protected]>
wrote:

> Hi Bob,
>
> Thanks for sharing your experience and work case for fixing the issue, Yes
> It worked for me too, removed the failover for that specific subnet and
> then started dhcpd on both the appliances then added it back again now
> everything looks good
>
> With lots of subnets, all using failover, I see this error fairly often
> ---->Bob, do you observe/feel any common steps in your environment which
> might trigger this type of issue ? Just want to know what triggered this
> inconsistency in the lease file
>
> Thanks for quick responses to all
>
> On Tue, Aug 17, 2021 at 7:39 PM Bob Harold <[email protected]> wrote:
>
>> With lots of subnets, all using failover, I see this error fairly often.
>> I am using a vendor IPAM solution, so my fix is to remove the failover
>> server from the subnet config, push out new dhcpd.conf files, then put it
>> back and push again.  Under the covers, that actually does:
>> - Remove the subnet completely from the second server, and reload dhcpd.
>> The server will drop all the leases for that subnet since the subnet is
>> gone.
>> - Remove the "failover" line for that subnet on the primary server and
>> reload dhcp.
>> - Add the failover line back in and reload the primary.
>> - Add the subnet to the secondary again.
>>
>> That is what works for me.
>>
>> --
>> Bob Harold
>> DNS and DHCP Hostmaster - UMNet
>> Information and Technology Services (ITS)
>> [email protected]
>>
>>
>> On Tue, Aug 17, 2021 at 9:57 AM Abdul Khader <[email protected]> wrote:
>>
>>> Hi Kraishak
>>> Check the communication is happening on port 647 on both the servers
>>> using tcpdump -i any port 647
>>> Please also check if there are multiple entries my state and partner
>>> state. Feel both the servers are not in sync. Can you also check if the
>>> discovers from client is landing on both the servers ? If you are using
>>> split 128 then the traffic should land on both the Nodes. Check your ip
>>> helper (relay) to make sure it's configured to send to both the Nodes.
>>>
>>> Regards
>>>
>>>
>>> On Tue, 17 Aug 2021, 17:11 Kraishak Mahtha, <[email protected]>
>>> wrote:
>>>
>>>> Hi  Abdul Khader,
>>>>
>>>> I have declared as follows:
>>>>
>>>> Configuration file from primary
>>>> =========================
>>>> failover peer "peer-host" {
>>>>         primary;
>>>>         address 192.168.56.156;
>>>>         port 647;
>>>>         peer address 192.168.56.178;
>>>>         peer port 647;
>>>>         max-response-delay 30;
>>>>         max-unacked-updates 30;
>>>>         load balance max seconds 3;
>>>>         mclt 1800;
>>>>         split 128;
>>>> }
>>>> subnet 192.168.56.0 netmask 255.255.255.0 {
>>>>         pool {
>>>>                 failover peer "peer-host";
>>>>                 range 192.168.56.5 192.168.56.54;
>>>>         }
>>>>                 option domain-name "test.com";
>>>>                 option routers 192.168.56.1;
>>>>                 option subnet-mask 255.255.255.0;
>>>>         }
>>>>
>>>> Configuration file from failover
>>>> ======================
>>>> failover peer "peer-host" {
>>>>         secondary;
>>>>         address 192.168.56.178;
>>>>         port 647;
>>>>         peer address 192.168.56.156;
>>>>         peer port 647;
>>>>         max-response-delay 30;
>>>>         max-unacked-updates 30;
>>>>         load balance max seconds 3;
>>>> }
>>>> subnet 192.168.56.0 netmask 255.255.255.0 {
>>>>         pool {
>>>>                 failover peer "peer-host";
>>>>                 range 192.168.56.5 192.168.56.54;
>>>>         }
>>>>                 option domain-name "test.com";
>>>>                 option routers 192.168.56.1;
>>>>                 option subnet-mask 255.255.255.0;
>>>>         }
>>>>
>>>> On the primary log it shows as :* total 50  free 0  backup 0*
>>>> *Aug 17 17:15:48 dhcp1 dhcpd[12130]: peer peer-host: Got POOLREQ,
>>>> answering negatively!  Peer may be out of leases or database inconsistent.*
>>>>
>>>> but in the failover log it shows as
>>>> Aug 17 17:14:48 dhcp2 dhcpd[1902]: balancing pool bf05b0
>>>> 192.168.56.0/24  *total 50  free 50  backup 0  lts -25  max-own (+/-)5
>>>> * (requesting peer rebalance!)
>>>> Aug 17 17:14:48 dhcp2 dhcpd[1902]: balanced pool bf05b0 192.168.56.0/24  total
>>>> 50  free 50  backup 0  lts -25  max-misbal 8
>>>>  pool response: 0 leases
>>>>
>>>> because of some reason the pool is not getting balanced between the
>>>> primary and failover
>>>>
>>>>
>>>> Also I have a problem in tracking my thread previously from *http://isc-dhcp-users
>>>> <http://isc-dhcp-users>* link I used to track and reply but now it is
>>>> not working, and tried searching the other links I found this *https://lists.isc.org/pipermail/dhcp-users/
>>>> <https://lists.isc.org/pipermail/dhcp-users/> *to track but I cannot
>>>> see a reply option in that web page
>>>>
>>>>
>>>>
>>>> On Tue, Aug 17, 2021 at 5:41 PM Kraishak Mahtha <[email protected]>
>>>> wrote:
>>>>
>>>>> Hi,
>>>>> I am using ISC DHCP in primary and failover mode and I am getting
>>>>> issue that clients are not getting leases and when I checked for the
>>>>> service logs I see as
>>>>> Primary Logs:
>>>>> ==========
>>>>> Aug 17 17:15:48 dhcp1 dhcpd[12130]: balancing pool f6f5f0
>>>>> 192.168.56.0/24  total 50  free 0  backup 0  lts 0  max-own (+/-)0
>>>>> Aug 17 17:15:48 dhcp1 dhcpd[12130]: balanced pool f6f5f0
>>>>> 192.168.56.0/24  total 50  free 0  backup 0  lts 0  max-misbal 0
>>>>> Aug 17 17:15:48 dhcp1 dhcpd[12130]: peer peer-host: Got POOLREQ,
>>>>> answering negatively!  Peer may be out of leases or database inconsistent.
>>>>>
>>>>> Failover Logs
>>>>> ==========
>>>>> Aug 17 17:14:48 dhcp2 dhcpd[1902]: balancing pool bf05b0
>>>>> 192.168.56.0/24  total 50  free 50  backup 0  lts -25  max-own (+/-)5
>>>>>  (requesting peer rebalance!)
>>>>> Aug 17 17:14:48 dhcp2 dhcpd[1902]: balanced pool bf05b0
>>>>> 192.168.56.0/24  total 50  free 50  backup 0  lts -25  max-misbal 8
>>>>>  pool response: 0 leases
>>>>>
>>>>> I tried searching the forums and many of them suggested that there
>>>>> might be inconsistency between the configuration file and leases database,
>>>>> I cross verified the configs they are good and regarding the leases file
>>>>> can we manually do any operation to make them in sync ?
>>>>>
>>>>> I tried checking the status of the primary and failover in the lease
>>>>> file but they are in normal-normal,
>>>>> cat dhcpd.leases | egrep "my state|partner state" | tail -2
>>>>>   my state normal at 2 2021/08/17 16:41:09;
>>>>>   partner state normal at 2 2021/08/17 17:01:17;
>>>>>
>>>>> Has anyone faced a similar issue/Any suggestions of how to fix the
>>>>> issue,
>>>>> Can we manually send requests for the DHCP service to do the pool
>>>>> balance and sync the leases for that specific subnet ?
>>>>>
>>>>>
>>>>> Any help/suggestion would be much appreciated
>>>>> Thanks
>>>>> Kraishak
>>>>>
>>>>>
>>>>> _______________________________________________
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>>>
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>>>
>>

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