[Openstack] Allocating dynamic IP to the VMs

Sylvain Bauza sylvain.bauza at digimind.com
Mon Mar 25 10:53:53 UTC 2013


The basic troubleshooting steps for L3 mapping are :
1. make sure your DNAT/SNAT entries have been populated correctly (using 
'iptables -t nat -L -n )
2. monitor your qg-XXXXX interface making sure SNAT is working properly 
(using 'tcpdump -i qg-XXXX -nn) and checking that you actually have 
*two* TCP requests with the same id (the first one with the private IP, 
the second one with the public IP)
3. make sure you activated ip_forward in /etc/sysctl.conf and either 
reboot or sysctl -w the value (and restart quantum-l3-agent in this case)


If these 3 steps are OK, then you have a gateway issue, not related to 
Quantum.

-Sylvain

Le 24/03/2013 15:49, Chathura M. Sarathchandra Magurawalage a écrit :
> Thanks Sylvain,
>
> I have tried this, but does not seem to work. I can allocate the 
> floating ip to the VM but it is not accessible from the physical 
> network. I can not ping to it from the controller or any other 
> physical nodes.
>
> Any idea?
>
> On 19 March 2013 16:14, Sylvain Bauza <sylvain.bauza at digimind.com 
> <mailto:sylvain.bauza at digimind.com>> wrote:
>
>     As per
>     http://docs.openstack.org/folsom/openstack-network/admin/content/demo_logical_network_config.html
>     but slightly modified as per CLI help,
>
>     quantum net-create ext_net --tenant-id $TENANT_ID --router:external=True
>     quantum subnet-create --ip_version 4 --allocation-pool start=192.168.2.151,end=192.168.2.240 \
>       --gateway 192.168.2.253 <id_of_ext_net>192.168.2.0/24  <http://192.168.2.0/24>  -- --enable_dhcp=False
>
>
>     It will create ext_net subnet with preallocated IP range. For each
>     VM, allocate floating IP from this pool and then associate it with
>     the internal port.
>
>     Hope it can helps,
>     -Sylvain
>
>     Le 19/03/2013 13:44, Chathura M. Sarathchandra Magurawalage a écrit :
>>     Thanks.
>>
>>     its 192.168.2.0/24 <http://192.168.2.0/24>
>>
>>     free ip range: 192.168.2.151 192.168.2.240
>>
>>     gw/dhcp server: 192.168.2.253
>>
>>
>>     On 19 March 2013 08:28, Sylvain Bauza <sylvain.bauza at digimind.com
>>     <mailto:sylvain.bauza at digimind.com>> wrote:
>>
>>         In that case, please refer to my previous e-mail : use
>>         floating IPs bound to the same physical network.
>>         That's up to you to know which IP pools are available inside
>>         your network. Once you get one, create a external Quantum
>>         subnet defined with this IP range.
>>
>>         Sorry, I have feeling to explain again and again. If you
>>         still don't catch the point, could you please then tell me
>>         your physical net/CIDR, your free IP range and your gateway,
>>         and I'll mix you up the command to issue.
>>
>>         -Sylvain
>>
>>         Le 18/03/2013 18:02, Chathura M. Sarathchandra Magurawalage a
>>         écrit :
>>>         Thanks Sylvain,
>>>
>>>         There must be a way of doing this without having to do
>>>         anything with my default gateway of my physical network? .
>>>         Even if I have to I do not wan to do anything to the
>>>         physical gateway. All I need is a way to let the VMs get a
>>>         dynamic IP from the physical network. How can I do this. For
>>>         example this can be done on virtual box using a bridge
>>>         adapter which maps the VM in to the physical network.
>>>
>>>         On 18 March 2013 16:05, Sylvain Bauza
>>>         <sylvain.bauza at digimind.com
>>>         <mailto:sylvain.bauza at digimind.com>> wrote:
>>>
>>>             Could you please tell me your "physical network" CIDR ?
>>>             Anyway, what you need is not requiring having a floating
>>>             IP pool inside the same network, you can also play with
>>>             static routing : if your physical host does have a
>>>             default gw, you can create a static route from this gw
>>>             to the VM network gateway. And on the VM network
>>>             gateway, do the same...
>>>
>>>             -Sylvain
>>>
>>>             Le 18/03/2013 16:53, Chathura M. Sarathchandra
>>>             Magurawalage a écrit :
>>>>             Hey Sylvain,
>>>>
>>>>             Basically what I need is to have the VMs mapped to my
>>>>             physical network so that my physical hosts can directly
>>>>             access the VMs. How can I do this?
>>>>
>>>>             Thanks.
>>>>
>>>>
>>>>             On 18 March 2013 15:50, Sylvain Bauza
>>>>             <sylvain.bauza at digimind.com
>>>>             <mailto:sylvain.bauza at digimind.com>> wrote:
>>>>
>>>>                 Hi,
>>>>
>>>>                 I don't understand your business. Should you have a
>>>>                 192.168.1.0/24 <http://192.168.1.0/24> network for
>>>>                 management, you could also assign an external
>>>>                 network with Quantum based on the same subnet (ie.
>>>>                 192.168.1.0/24 <http://192.168.1.0/24>).
>>>>                 When creating a floating IP pool, Quantum does
>>>>                 require at least 3 things :
>>>>                  - the CIDR
>>>>                  - the beginning and ending IPs
>>>>                  - the external gateway
>>>>
>>>>                 So, based on what I previously said, you only need
>>>>                 to create a 192.168.1.0/24 <http://192.168.1.0/24>
>>>>                 in Quantum with .1-.100 (for example) as the range,
>>>>                 .254 being the external gateway.
>>>>
>>>>                 Thanks,
>>>>                 -Sylvain
>>>>
>>>>                 Le 18/03/2013 16:29, Chathura M. Sarathchandra
>>>>                 Magurawalage a écrit :
>>>>>                 anyone?
>>>>>
>>>>>                 On 17 March 2013 21:33, Chathura M. Sarathchandra
>>>>>                 Magurawalage <77.chathura at gmail.com
>>>>>                 <mailto:77.chathura at gmail.com>> wrote:
>>>>>
>>>>>                     After reading a little bit more, I think I
>>>>>                     have found what I need. It is  a provider
>>>>>                     network that I need for the VMs so that they
>>>>>                     can get access to the other resources in my
>>>>>                     main network ( such as other physical hosts
>>>>>                     that are connected to the same network ).
>>>>>
>>>>>                     My question is, is it possible to do this
>>>>>                     alongside the use case that I have followed (
>>>>>                     Provider router with private networks)?
>>>>>
>>>>>                     If so how can I do this?
>>>>>
>>>>>                     Thanks.
>>>>>
>>>>>
>>>>>                     On 16 March 2013 01:46, Chathura M.
>>>>>                     Sarathchandra Magurawalage
>>>>>                     <77.chathura at gmail.com
>>>>>                     <mailto:77.chathura at gmail.com>> wrote:
>>>>>
>>>>>                         Hello,
>>>>>
>>>>>                         I want to know how I can allocate a
>>>>>                         dynamic IP to the VM from the same network
>>>>>                         as the openstack hosts
>>>>>                         (controller/network-node/compute node)
>>>>>                         network/management network . For example,
>>>>>                         in virtual box you can give your VM an IP
>>>>>                         from the host's network using a Bridge
>>>>>                         adapter. How can I do this in openstack?
>>>>>
>>>>>                         From what I understand floating IP's are
>>>>>                         used when you have a public IP
>>>>>                          (which is static) to be allocated to VM's.
>>>>>                         My openstack installation architecture:
>>>>>                         http://docs.openstack.org/folsom/basic-install/content/basic-install_architecture.html
>>>>>
>>>>>                         Quantum use case:
>>>>>                         http://docs.openstack.org/trunk/openstack-network/admin/content/use_cases_single_router.html
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>                 _______________________________________________
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>>>>>                 More help   :https://help.launchpad.net/ListHelp
>>>>
>>>>
>>>
>>>
>>
>>
>
>

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