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VM IP address not assigned

asked 2016-12-30 06:30:10 -0600

fabry00 gravatar image

updated 2017-01-04 06:31:28 -0600

Hi all, I'm new on Openstack.

The scenario is thew following

My company asked me to extend an old Openstack cluster. The cluster is composed by:

  • 1 Controller node
  • 1 Network node
  • 6 Compute nodes

All the computers has 1 NIC then they used OpenvSwitch to simulate 3 NIC on each computer:

  • (public ip address)

The Openstack version installed is Icehouse (2014.1.5) on Ubuntu Server 14.04.5 LTS. This cluster is working fine then I cannot change nothing or update the Openstack version.. I have only to add some Compute nodes.

I added a new compute node using the following procedure:

  • I cloned the Compute6 node using Clonezilla ( I didn't install openstack from scratch because I need to add 28 Compute nodes and in this way I think that is faster)
  • I restored the cloned image to the new node (same hardware)
  • I restarted the new node with the network cable disconnected and changed the following configurations:
    • hostname and hosts file (to change the node hostname "node9")
    • /etc/network/interface to change the 3 ip static ip addresses ( / /
    • in /etc/nova/nova.conf I updated: my_ip and vncserver_proxyclient_address configuration with the new ip address (
  • On Controller node, I added the new Openstack GRE:
    • sudo ovs-vsctl add-port br-int0 gre9
    • sudo ovs-vsctl set interface gre9 type=gre options:remote_ip=
  • I connected the network cable to the new Compute node and restarted it

From Horizon interface I can see the new Compute node under "Host Aggregates" -> "Availability Zones table" -> "nova row" (where there are all others compute nodes.

Also from the controller node I can ping the 3 Ip addresses of the new Compute ( / /

10 packets transmitted, 10 received, 0% packet loss, time 8999ms rtt min/avg/max/mdev = 0.154/0.185/0.240/0.029 ms

The problem

If I create a new instance (using an existing image in our Openstack cluster), it is deployed successfully on the new compute node but the new Instance doesn't receive the IP address from the Openstack dhcp . If I create a new instance on an old Compute node (using the same image) , this instance receive the Ip address from the Openstack dhcp.

For this reason I think that I did something wrong with the new ComputeNode but I cannot understand the problem.

in the /var/log/nova/nova-compute.log on the node9 there aren't significant errors.

Additional Information

nova network-list

| ID                                   | Label    | Cidr |
| 01b1ffdc-300a-436c-be65-1a1ab866a276 | demo-net | -    |
| ddcf7ee5-9730-47a1-9ddb-85dbd16e10c9 | ext-net  | -    |

neutron subnet-list 

| id                                   | name        | cidr           | allocation_pools                                 |
| 003f7baa-3be9-43f7-bca7-b41a5a27bc9e | ext-subnet  |  | {"start": "", "end": ""}  |
| 202a8b8c-b529-43b0-a519-97f83ec7f256 | demo-subnet | | {"start": "", "end": ""} |

sudo nova-manage vm ...
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2 answers

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answered 2017-01-17 06:49:47 -0600

fabry00 gravatar image

I solved the problem.

It was a wrong configuration in


Since I cloned the Compute node with clonezilla, I had to change the local_ip config in /etc/neutron/plugins/ml2/ml2_conf.ini

Thanks to all

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answered 2017-01-02 11:41:51 -0600

tze gravatar image

On new host changed the network interface, so check if the os firewall added the internal interfaces on some restricted zone. Check the conectivity of instanse with the dhcp's Net Namespace on network node. Maybe the iptables in netns blocks the dhcp calls. If you add manual ip address on vm has connectivity with assisiated subnet?

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Thank you. I've added the output of ifconfig and iptables -L at the post.I don't see anything strange, Could you check please? Also I tried to assign the ip to the VM but nothing changed, I cannot ping anything. How can I "Check the conectivity of instanse with the dhcp's Net Namespace on network"?

fabry00 gravatar imagefabry00 ( 2017-01-04 05:00:47 -0600 )edit

Using tcpdump on the new Compute node I saw the VM dhcp request (I've updated the post with tcpdump output)

fabry00 gravatar imagefabry00 ( 2017-01-04 06:32:37 -0600 )edit

Can you post the output of neutron agent-list and 'ip netns list' on the network node ?

Sofiane68 gravatar imageSofiane68 ( 2017-01-05 07:26:55 -0600 )edit

@Sofiane68 Thank you for your time. I've already posted the output that you are looking for. Check the question above please (maybe you have to click on the link (more) at the bottom of the post to see the full question text Thank you again

fabry00 gravatar imagefabry00 ( 2017-01-05 07:57:24 -0600 )edit

I think the problem is the connection of two br-tun bridges. With command: "ovs.vsctl show" on both, netnode and new node you must see from one port on br-tun of type gre or vxlan. The ip's of this connection are configured on openvswitch_agent.ini in [ovs]\local_ip setting.

tze gravatar imagetze ( 2017-01-06 05:54:53 -0600 )edit

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Asked: 2016-12-30 06:04:45 -0600

Seen: 1,486 times

Last updated: Jan 17 '17