Open Stack

To follow up on the relay idea.  In our implementation we have looked at trying to enable ip_helper on the switches to forward dhcp to a set of defined neutron dhcp servers.  The issue is that this turns the dhcp requests from a broadcast packet to a unicast packet.  With the default way neutron configures each dhcp agent (in its own network name space) - I could not think of a way, outside of a total hack, to get the unicast packet into the correct namespace. 

___________________________________________________________________
Kris Lindgren
Senior Linux Systems Engineer
GoDaddy







On 2/25/16, 3:20 PM, "Carl Baldwin" <carl at ecbaldwin.net> wrote:

>(resending with reply-all)
>
>The routed networks work will include a change to the DHCP scheduler
>which will work something like this:
>
>1. Neutron subnets will have optional affinity to a segment
>2. DHCP agents will (somewhat indirectly) report which segments to
>which they are attached*.
>3. Where today, DHCP schedules networks to DHCP agents, tomorrow DHCP
>will schedule each segment to an agent that can reach it.  This will
>be predicated on 'enable_dhcp' being set on the subnets.
>
>There is an implicit assumption here that the operator will deploy a
>DHCP agent in each of the segments.  This will be documented in the
>guide.
>
>Down the road, I really think we should continue to explore other
>possibilities like DHCP relay or a DHCP responder on the compute host.
>But, that should be considered an independent effort.
>
>Carl
>
>* they already do this by reporting physical_network in bridge mappings
>
>On Thu, Feb 25, 2016 at 11:30 AM, Tim Bell <Tim.Bell at cern.ch> wrote:
>>
>> The CERN guys had some concerns on how dhcp was working in a segment environment. I’ll leave them to give details.
>>
>> Tim
>>
>>
>>
>>
>>
>> On 25/02/16 14:53, "Andrew Laski" <andrew at lascii.com> wrote:
>>
>>>
>>>
>>>On Thu, Feb 25, 2016, at 05:01 AM, Tim Bell wrote:
>>>>
>>>> CERN info added.. Feel free to come back for more information if needed.
>>>
>>>An additional piece of information we're specifically interested in from
>>>all cellsv1 deployments is around the networking control plane setup. Is
>>>there a single nova-net/Neutron deployment per region that is shared
>>>among cells? It appears that all cells users are splitting the network
>>>data plane into clusters/segments, are similar things being done to the
>>>control plane?
>>>
>>>
>>>>
>>>> Tim
>>>>
>>>>
>>>>
>>>>
>>>> On 24/02/16 22:47, "Edgar Magana" <edgar.magana at workday.com> wrote:
>>>>
>>>> >It will be awesome if we can add this doc into the networking guide  :-)
>>>> >
>>>> >
>>>> >Edgar
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >On 2/24/16, 1:42 PM, "Matt Riedemann" <mriedem at linux.vnet.ibm.com> wrote:
>>>> >
>>>> >>The nova and neutron teams are trying to sort out existing deployment
>>>> >>network scenarios for cells v1 so we can try and document some of that
>>>> >>and get an idea if things change at all with cells v2.
>>>> >>
>>>> >>Therefore we're asking that deployers running cells please document
>>>> >>anything you can in an etherpad [1].
>>>> >>
>>>> >>We'll try to distill that for upstream docs at some point and then use
>>>> >>it as a reference when talking about cells v2 + networking.
>>>> >>
>>>> >>[1] https://etherpad.openstack.org/p/cells-networking-use-cases
>>>> >>
>>>> >>--
>>>> >>
>>>> >>Thanks,
>>>> >>
>>>> >>Matt Riedemann
>>>> >>
>>>> >>
>>>> >>_______________________________________________
>>>> >>OpenStack-operators mailing list
>>>> >>OpenStack-operators at lists.openstack.org
>>>> >>http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>>>> >_______________________________________________
>>>> >OpenStack-operators mailing list
>>>> >OpenStack-operators at lists.openstack.org
>>>> >http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>>>> _______________________________________________
>>>> OpenStack-operators mailing list
>>>> OpenStack-operators at lists.openstack.org
>>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>>>> Email had 1 attachment:
>>>> + smime.p7s
>>>>   4k (application/pkcs7-signature)
>>>
>>>_______________________________________________
>>>OpenStack-operators mailing list
>>>OpenStack-operators at lists.openstack.org
>>>http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>>
>> _______________________________________________
>> OpenStack-operators mailing list
>> OpenStack-operators at lists.openstack.org
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>>
>
>_______________________________________________
>OpenStack-operators mailing list
>OpenStack-operators at lists.openstack.org
>http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators