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Instances dont get IP addresses

asked 2015-10-11 13:06:26 -0600

ruben gravatar image


I am having a problem with my instances not getting an IP address on any of my two compute nodes. Horizon tells me it has a IP address but it does not have one when i boot it. When i try get an IP trough "dhclient -v" it wont find a server that can give a IP.

I am running multinode Openstack Juno cluster on CentOS 7. I did not use RDO.

The neutron logs on the neutron server do not give any error messages. Neutron agent-list gives the following output

    [root@controller01 ~]# neutron agent-list
| id                                   | agent_type         | host                    | alive | admin_state_up | binary                    |
| 07657445-625f-4efd-b99e-da69bd833384 | Open vSwitch agent |    | :-)   | True           | neutron-openvswitch-agent |
| 4236d031-069c-4001-84e5-a2f260c278af | L3 agent           | | :-)   | True           | neutron-l3-agent          |
| 42aae6ef-4601-4492-bcc5-8af216135e82 | Open vSwitch agent | | :-)   | True           | neutron-openvswitch-agent |
| a74a2cc8-b8d8-447d-a485-5dce1c653c1d | DHCP agent         | | :-)   | True           | neutron-dhcp-agent        |
| abf4402c-5017-44c6-bed6-520f9f1f87a6 | Metadata agent     | | :-)   | True           | neutron-metadata-agent    |
| c3e7537e-f986-4c0f-a893-49efe5acd54a | Open vSwitch agent |    | :-)   | True           | neutron-openvswitch-agent |
| cc325f2c-61fd-4273-a266-e5f10b13f269 | DHCP agent         | | :-)   | True           | neutron-dhcp-agent        |

Thanks! Ruben

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Centos + networking problems = firewall. Check whether the DHCP port on the network node is open.

Bernd Bausch gravatar imageBernd Bausch ( 2015-10-11 22:01:47 -0600 )edit

3 answers

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answered 2015-10-16 04:53:26 -0600

smcas gravatar image

Hello , I am facing the same problem. My DHCP agent and dnsmasq is working properly but packets are not reaching the VM. Moreover, ip netns also shows nothing - no namespaces. As suggested by Bernd regarding firewall rules, Please tell what firewall rules (ingress and egress) need to be applied on 3-node openstack icehouse and which ports need to be opened on all nodes ?

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please share the packet it would give a clear idea , as , who/what is blocking the packets. gravatar ( 2015-10-16 20:23:38 -0600 )edit

hi, ritesh please refer this link, here i posted some output of packet flow

smcas gravatar imagesmcas ( 2015-10-19 05:33:59 -0600 )edit

answered 2015-10-11 22:07:20 -0600

germs gravatar image

When you run dhclient from within the instance (or monitor during the boot process), and dump the traffic from the compute, do you see the dhcp request? What about from the controller, is it making it that far?

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answered 2015-10-12 23:21:46 -0600 gravatar image

Best way to solve these type of issues , is to track the packets. It will give you better idea of the issue. If you can see the IP on horizon but the instance did not get that , It mean either the DHCP is not working fine or the packets are not reaching VMs. Your DHCP agent seems to be fine. So , the issue is packets not reaching the DHCP agent from VM or to VM from DHCP agent. As suggested by Bernd , check the firewall rules , tagging etc and verify the path of DHCP messages.

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Asked: 2015-10-11 13:06:26 -0600

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Last updated: Oct 16 '15