[one-users] Setting up private networks for VM

Prakhar Srivastava prakhar.apj at gmail.com
Thu Apr 7 22:27:08 PDT 2011


Hi Jaime,
I did as you said. I specified the same bridge eth0 for both the public and
the private network. I created two VMs with both public and private
interfaces. I could ping private IPs from within the virtual machines.
However I was surprised to see that if I create one VM with both public and
private interfaces and one VM with just the private interface, I am not able
to ping the private only VM from the both-public-and-private VM which was
something I wished to do.

In a general case, I wish to have just a single both-public-and-private
VM(call it master VM) for a user and other VMs should have just the private
interface so that it can be accessed from the master VM.

Is this behavior normal or I am missing something ??

Regards,
Prakhar

On Thu, Apr 7, 2011 at 2:05 PM, Jaime Melis <jmelis at opennebula.org> wrote:

> Hi Prakhar,
>
> you need to use the same bridge, both for public and private networks:
> eth0.
>
> regards,
> Jaime
>
>
> On Wed, Apr 6, 2011 at 9:18 PM, Prakhar Srivastava <prakhar.apj at gmail.com>wrote:
>
>> Hi,
>> Thannx for the reply.
>> Using two NIC sections per VM (one has eth0 bridge and the other one has
>> eth1 as bridge) But I have a single bridge created on each of my cluster
>> nodes i.e. eth0. When I insert NIC for private network which has bridge as
>> "eth1", I get a error that eth1 bridge does not exist and the deployment
>> fails.eth0 acts as a bridge between my public network and the network
>> interfaces of VMs. This works fine.
>>
>> I want that a second NIC can be added to the VMs but it fails because of
>> the reason mentioned above.(there is no eth1 bidge).
>>
>> Regards,
>> Prakhar
>>
>>
>> On Wed, Apr 6, 2011 at 9:18 PM, Jaime Melis <jmelis at opennebula.org>wrote:
>>
>>> Hi Prakhar,
>>>
>>> The scenario you've described is very easily achievable, you only need to
>>> create another private network vnet instance (created with the onevnet
>>> utility) and add two NIC sections per VM, one for the public NIC and one for
>>> the private one.
>>>
>>> It has one drawback, though, if you do this you will not be able to use
>>> the ebtables hook for network isolation, therefore someone using one of your
>>> VMs might be able to do MAC spoofing. But other than that it should work
>>> perfectly.
>>>
>>> cheers,
>>> Jaime
>>>
>>> On Mon, Apr 4, 2011 at 12:24 PM, Prakhar Srivastava <
>>> prakhar.apj at gmail.com> wrote:
>>>
>>>> Hi,
>>>> By private networks, I mean the virtual network created by opennebula
>>>> onevnet utility. Consider the scenario where I have 4 VMs running in my
>>>> opennebula cloud setup. All of them has  a public IP (allocated from a
>>>> virtual network created by using onevnet utility) thats accessible from my
>>>> network(LAN) . Its easy enough to access because it falls under the same
>>>> network in which I am. What if I want to attach another interface to the
>>>> VMs, so that I can assign private IPs to them .This is handy if you want to
>>>> have more VMs than the number of public IPs available to you. Hope this
>>>> makes sense.
>>>> My question i do I need to have another physical NIC on all my cluster
>>>> nodes for this.If not, please suggest a solution.
>>>>
>>>> Regards,
>>>> Prakhar
>>>>
>>>> On Mon, Apr 4, 2011 at 11:33 AM, Prakhar Srivastava <
>>>> prakhar.apj at gmail.com> wrote:
>>>>
>>>>> Hi,
>>>>> I wanted to set up private networks for VMs in my opennebula setup. Is
>>>>> it necessary to have two physical NICs on the cluster nodes for setting
>>>>> private networks. If yes, is there any alternative to it so that I can use
>>>>> my VMs using their private IPs.
>>>>>
>>>>> Regards,
>>>>> Prakhar
>>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Users mailing list
>>>> Users at lists.opennebula.org
>>>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>>>>
>>>>
>>>
>>>
>>> --
>>> Jaime Melis, Cloud Technology Engineer/Researcher
>>> Major Contributor
>>> OpenNebula - The Open Source Toolkit for Cloud Computing
>>> www.OpenNebula.org | jmelis at opennebula.org
>>>
>>
>>
>
>
> --
> Jaime Melis, Cloud Technology Engineer/Researcher
> Major Contributor
> OpenNebula - The Open Source Toolkit for Cloud Computing
> www.OpenNebula.org | jmelis at opennebula.org
>
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