[Openstack] Kilo Devstack - DCHP is not assigning IPs to the VMs

Ahmed Medhat a.medhat.h at gmail.com
Mon Jun 20 08:47:25 UTC 2016


I would like also to add something may helps; that I did the devstack
installation before on Centos and I did not fce this problem, but Now I am
using Ubuntu 14.04 so may be the issue is here ?

Best regards,
Ahmed

On Monday, June 20, 2016, Ahmed Medhat <a.medhat.h at gmail.com> wrote:

> i add it but it is not working also.
> May be This  iptables rule for traffic reaching the dhcp port but there
> should be one in the other direction and be dport 67 ?
>
> Best regards,
> Ahmed
>
> On Monday, June 20, 2016, Neil Jerram <neil at tigera.io
> <javascript:_e(%7B%7D,'cvml','neil at tigera.io');>> wrote:
>
>> In that case I guess you are somehow missing the iptables rule that fills
>> in the CHECKSUM properly on DHCP replies.  Is the problem fixed if you add
>> the following iptables rule in the DHCP namespace on the network node?
>>
>> iptables -A POSTROUTING -t mangle -p udp --dport 68 -j CHECKSUM
>> --checksum-fill
>>
>>     Neil
>>
>>
>>
>>
>> On Mon, Jun 20, 2016 at 9:30 AM Ahmed Medhat <a.medhat.h at gmail.com>
>> wrote:
>>
>>> Hi Neil,
>>>
>>> Thanks for your reply.
>>>
>>> I have done tcpdump on dhcp port of the private network in Openstack and
>>> I saw the received dhcp request and replies. It seems tgat the replies are
>>> not received to the VM.
>>> I want to add tgat if I adjusted the ip manually inside the VM instance
>>> , it works fine and I can ping the dhcp ip 11.0.0.2 in my case.
>>>
>>> I hope this info shows you where could be the problem I have.
>>>
>>> Best regards,
>>> Ahmed
>>>
>>>
>>> On Monday, June 20, 2016, Neil Jerram <neil at tigera.io> wrote:
>>>
>>>> Hi Ahmed,
>>>>
>>>> Unfortunately there are many possible reasons - and different ones
>>>> depending on your setup.
>>>>
>>>> I will guess, though, that you're using a default OVS setup, without
>>>> DVR.  In that case DHCP should be provided by Dnsmasq running on your
>>>> network node, and I would start by checking for that process and looking at
>>>> its logs (which could be in /var/log/syslog, /var/log/messages, journalctl,
>>>> ...) to see if there is any sign of DHCP requests being received, and then
>>>> whether Dnsmasq sends any DHCP responses.
>>>>
>>>> Regards,
>>>>      Neil
>>>>
>>>>
>>>> On Sat, Jun 18, 2016 at 1:34 PM Ahmed Medhat <a.medhat.h at gmail.com>
>>>> wrote:
>>>>
>>>>> Hi All,
>>>>>
>>>>> I have installed kilo devstack and have a problem with dhcp, it is not
>>>>> assigning IPs to the VMs.
>>>>> What are the reasons for that ?
>>>>>
>>>>> Best regards,
>>>>> Ahmed
>>>>> _______________________________________________
>>>>> Mailing list:
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>>>>> Post to     : openstack at lists.openstack.org
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>>>>>
>>>>
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