Mailing List Archive: OpenStack: Operators

[OpenStack-Operators][Neutron] Config options

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john.griffith at solidfire

Aug 4, 2013, 8:54 AM

Post #1 of 4 (35 views)
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[OpenStack-Operators][Neutron] Config options

Hey Everyone,

I have a specific use case that I'm trying to use in OpenStack.

My Compute Node has two public Nics (one for data/iscsi (10G) and one for
general public net access (1G)), both networks have their own DHCP server.
Each compute node also has an additional 10G network for OpenSack
management.

Here's what I've been trying to get working:
* assign both public networks to the instances on boot
* utilize the corporate DHCP server to handle IP assignment and config for
both of those networks on the instance.

I have not been able to get this to work and was wondering if any Neutron
folks (or anybody else for that matter) had any tips on how to configure
this?

I'm using KVM/Libvirt with openvswitch, but I'm willing to change things
around if needed to make this work.

Thanks,
John

lorin at nimbisservices

Aug 8, 2013, 7:39 PM

Post #2 of 4 (23 views)
Permalink

Re: [OpenStack-Operators][Neutron] Config options [In reply to]

Hi John:

I don't think OpenStack supports an external DHCP server, because there's
no mechanism for OpenStack to determine which IP addresses have been
assigned to the instances. You could configure the OVS plugin in flat mode
for each of the two physical networks, but you wouldn't know what the IP
addresses were of the instances after they booted.

Lorin

On Sun, Aug 4, 2013 at 11:54 AM, John Griffith
<john.griffith [at] solidfire>wrote:

> Hey Everyone,
>
> I have a specific use case that I'm trying to use in OpenStack.
>
> My Compute Node has two public Nics (one for data/iscsi (10G) and one for
> general public net access (1G)), both networks have their own DHCP server.
> Each compute node also has an additional 10G network for OpenSack
> management.
>
> Here's what I've been trying to get working:
> * assign both public networks to the instances on boot
> * utilize the corporate DHCP server to handle IP assignment and config for
> both of those networks on the instance.
>
> I have not been able to get this to work and was wondering if any Neutron
> folks (or anybody else for that matter) had any tips on how to configure
> this?
>
> I'm using KVM/Libvirt with openvswitch, but I'm willing to change things
> around if needed to make this work.
>
> Thanks,
> John
>
> _______________________________________________
> OpenStack-operators mailing list
> OpenStack-operators [at] lists
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>
>

--
Lorin Hochstein
Lead Architect - Cloud Services
Nimbis Services, Inc.
www.nimbisservices.com

dan at nicira

Aug 9, 2013, 8:16 AM

Post #3 of 4 (22 views)
Permalink

Re: [OpenStack-Operators][Neutron] Config options [In reply to]

Yeah, this basically comes down to what entity is going to be the
authoritative source of IP address assignment. Quantum... errr, Neutron
assigns IP addresses when a new NIC is allocated, but unless you have
external logic to pull those IP address assignments out of Neutron (e.g.,
via the API) and into your corporate DHCP server, the DHCP response to the
VM will not match the one assigned by Neutron.

Another approach that is possible is to have an some logic outside of
OpenStack pick the MAC + IP address(es) to be used by a VM. This logic
would then push this information to the DHCP server, and "push" it to
Neutron by creating a port with that MAC + IP on the desired network, and
then passing in that port-id when booting the VM. This is the designed way
to bypass having Neutron allocate an IP from a pool on its own.

Making the Neutron IPAM more pluggable so that it could, for example,
interact with the corporate DHCP when allocating IPs for certain networks
is something that has been discussed and would be valuable, though I am not
personally aware of anything in progress on that end.

Dan

On Thu, Aug 8, 2013 at 7:39 PM, Lorin Hochstein <lorin [at] nimbisservices>wrote:

> Hi John:
>
> I don't think OpenStack supports an external DHCP server, because there's
> no mechanism for OpenStack to determine which IP addresses have been
> assigned to the instances. You could configure the OVS plugin in flat mode
> for each of the two physical networks, but you wouldn't know what the IP
> addresses were of the instances after they booted.
>
> Lorin
>
>
> On Sun, Aug 4, 2013 at 11:54 AM, John Griffith <
> john.griffith [at] solidfire> wrote:
>
>> Hey Everyone,
>>
>> I have a specific use case that I'm trying to use in OpenStack.
>>
>> My Compute Node has two public Nics (one for data/iscsi (10G) and one for
>> general public net access (1G)), both networks have their own DHCP server.
>> Each compute node also has an additional 10G network for OpenSack
>> management.
>>
>> Here's what I've been trying to get working:
>> * assign both public networks to the instances on boot
>> * utilize the corporate DHCP server to handle IP assignment and config
>> for both of those networks on the instance.
>>
>> I have not been able to get this to work and was wondering if any Neutron
>> folks (or anybody else for that matter) had any tips on how to configure
>> this?
>>
>> I'm using KVM/Libvirt with openvswitch, but I'm willing to change things
>> around if needed to make this work.
>>
>> Thanks,
>> John
>>
>> _______________________________________________
>> OpenStack-operators mailing list
>> OpenStack-operators [at] lists
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>>
>>
>
>
> --
> Lorin Hochstein
> Lead Architect - Cloud Services
> Nimbis Services, Inc.
> www.nimbisservices.com
>
> _______________________________________________
> OpenStack-operators mailing list
> OpenStack-operators [at] lists
> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>
>

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dan Wendlandt
Nicira, Inc: www.nicira.com
twitter: danwendlandt
~~~~~~~~~~~~~~~~~~~~~~~~~~~

danehans at cisco

Aug 9, 2013, 8:55 AM

Post #4 of 4 (21 views)
Permalink

Re: [OpenStack-Operators][Neutron] Config options [In reply to]

What if the Neutron L3 agent supported DHCP relay agent functionality? Since the agent is relaying the DHCP client/server exchange, it would have the necessary information to maintain a copy of the DHCP bindings.

Regards,
Daneyon Hansen
Software Engineer
Email: danehans [at] cisco
Phone: 303-718-0400
http://about.me/daneyon_hansen

From: Dan Wendlandt <dan [at] nicira<mailto:dan [at] nicira>>
Date: Friday, August 9, 2013 9:16 AM
To: Lorin Hochstein <lorin [at] nimbisservices<mailto:lorin [at] nimbisservices>>
Cc: "openstack-operators [at] lists<mailto:openstack-operators [at] lists>" <openstack-operators [at] lists<mailto:openstack-operators [at] lists>>, John Griffith <john.griffith [at] solidfire<mailto:john.griffith [at] solidfire>>
Subject: Re: [Openstack-operators] [OpenStack-Operators][Neutron] Config options

Yeah, this basically comes down to what entity is going to be the authoritative source of IP address assignment. Quantum... errr, Neutron assigns IP addresses when a new NIC is allocated, but unless you have external logic to pull those IP address assignments out of Neutron (e.g., via the API) and into your corporate DHCP server, the DHCP response to the VM will not match the one assigned by Neutron.

Another approach that is possible is to have an some logic outside of OpenStack pick the MAC + IP address(es) to be used by a VM. This logic would then push this information to the DHCP server, and "push" it to Neutron by creating a port with that MAC + IP on the desired network, and then passing in that port-id when booting the VM. This is the designed way to bypass having Neutron allocate an IP from a pool on its own.

Making the Neutron IPAM more pluggable so that it could, for example, interact with the corporate DHCP when allocating IPs for certain networks is something that has been discussed and would be valuable, though I am not personally aware of anything in progress on that end.

Dan

On Thu, Aug 8, 2013 at 7:39 PM, Lorin Hochstein <lorin [at] nimbisservices<mailto:lorin [at] nimbisservices>> wrote:
Hi John:

I don't think OpenStack supports an external DHCP server, because there's no mechanism for OpenStack to determine which IP addresses have been assigned to the instances. You could configure the OVS plugin in flat mode for each of the two physical networks, but you wouldn't know what the IP addresses were of the instances after they booted.

Lorin

On Sun, Aug 4, 2013 at 11:54 AM, John Griffith <john.griffith [at] solidfire<mailto:john.griffith [at] solidfire>> wrote:
Hey Everyone,

I have a specific use case that I'm trying to use in OpenStack.

My Compute Node has two public Nics (one for data/iscsi (10G) and one for general public net access (1G)), both networks have their own DHCP server. Each compute node also has an additional 10G network for OpenSack management.

Here's what I've been trying to get working:
* assign both public networks to the instances on boot
* utilize the corporate DHCP server to handle IP assignment and config for both of those networks on the instance.

I have not been able to get this to work and was wondering if any Neutron folks (or anybody else for that matter) had any tips on how to configure this?

I'm using KVM/Libvirt with openvswitch, but I'm willing to change things around if needed to make this work.

Thanks,
John

_______________________________________________
OpenStack-operators mailing list
OpenStack-operators [at] lists<mailto:OpenStack-operators [at] lists>
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators

--
Lorin Hochstein
Lead Architect - Cloud Services
Nimbis Services, Inc.
www.nimbisservices.com<http://www.nimbisservices.com>

_______________________________________________
OpenStack-operators mailing list
OpenStack-operators [at] lists<mailto:OpenStack-operators [at] lists>
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dan Wendlandt
Nicira, Inc: www.nicira.com<http://www.nicira.com>
twitter: danwendlandt
~~~~~~~~~~~~~~~~~~~~~~~~~~~

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