mithilarun's profile - activity

2019-04-03 12:44:38 -0500 commented question dnsmasq-dhcp - DHCPDISCOVER - no address available

What is the IP allocated by Neutron for this instance? Looking at what you posted, my first guess is that the DHCP agent responds back with that error because it doesn't have a record for the IP address for that MAC address.

2016-12-16 05:23:44 -0500 marked best answer Modular extension for Horizon

Is there a feature where I can add a field to a tab on Horizon using a model similar to extensions for Neutron? I want to be able to extend the fields available without directly modifying the source of Horizon, to make the changes I do easier to reuse.

Thanks in advance.

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2015-03-11 08:35:12 -0500 edited question "Cannot store contact Information" when updating info in OpenStack gerrit


While uploading my blueprint to gerrit, i am getting the following error to capture the contact information in my profile.

stack@ubuntu-47:~/openstack-specs/cinder-specs$ git config --list Kaligotla
stack@ubuntu-47:~/openstack-specs/cinder-specs$ git review

stack@ubuntu-47:~/openstack-specs/cinder-specs$ git review
**fatal: ICLA contributor agreement requires current contact information.
Please review your contact information:
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.**

When i login into the and try to update the contact information for my account, i get the following error.

Code Review - Error
Server Error
Cannot store contact Information

As a result i am unable to upload my blueprint docs into gerrit review system

I am not sure if I am doing something wrong here or if this is a bug. Is anyone else seeing it too?

Following is the screenshot of message.

image description

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2014-10-31 05:49:44 -0500 asked a question configure glance with a NFS server

I would like to configure glance that uses a NFS server to store the images. Additionally, I want my compute nodes to talk to this NFS server directly without having to go through the controller (where my glance service is running) when it downloads the images. Is there a way to do this?

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2014-08-27 04:09:08 -0500 commented question libvirt error in icehouse: vif_type=binding_failed

neutron agent-list

| id                                   | agent_type         | host     | alive | admin_state_up |
2014-08-26 11:31:17 -0500 commented answer Why does my instance not receive a DHCP address?

Do you see the neutron-dhcp-agent running on the controller?

2014-08-26 04:28:49 -0500 commented answer why do we need to unstack and stack it again when we turn off the system??

./ is what you're looking for. It starts all services and reloads your existing config.

2014-08-26 01:40:33 -0500 answered a question Why does my instance not receive a DHCP address?

This could be because of multiple issues:

  1. The VLAN range does not match the VLAN assigned to the VM.
  2. The security groups rules are filtering out all DHCP responses to the VM.
  3. If compute node and controller (where the DHCP server is running) are two separate machines, communication between them via the data link might be broken for whatever reasons.

To solve this, I suggest you run tcpdump on all interfaces from the VM to the physical port and see where the DHCP packet is being dropped. This should give us some clue on what could be the reason.

Also, please paste the contents of /etc/neutron/plugin.ini here. Would need to verify if the VLAN ranges are correct.

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2014-08-13 00:55:05 -0500 answered a question can we know where a particular VM is running (on which compute node)?

You can do this from Horizon as well.

Screen grab from my Havana controller

The "host" column that you see there will tell you on which compute node the VM is running on.

2014-08-13 00:50:43 -0500 edited question can we know where a particular VM is running (on which compute node)?
nova list

Shows me a list of running VMs. However, I would like to know which compute node is hosting the VM. Is there a way to do this?

2014-08-13 00:34:43 -0500 commented question neutron unit tests creation issues

Snip from email conversation:


Hi Mithil,

Ok. I found the solution. Yes the problem was due to invalid number of argument passed to the function update_router(). This function was existing function which I overrode in derived class, and there were some UT code still pointing to older version of update_router() method in Base class. I changed the UT code such that it now started calling derived class function which solved the problem.

Thanks anyways.


From: Mithil Arun []

Hi Vinod,

Call me Mithil :)

This is quite different from the problem I was facing.

From a quick look at the logs, it appears that you are passing too many arguments to your update router() function:

2014-08-11 09:21:56.994 | Traceback (most recent call last):
2014-08-11 09:21:56.994 |   File "neutron/api/v2/", line 87, in resource
2014-08-11 09:21:56.994 ...
2014-08-12 09:38:49 -0500 commented answer Running extensions for vendor specific mechanism drivers in ML2

Thanks for your answer. This is an interesting approach!

I'm wondering if there could be any unintended side effects though. ML2 does not really know about the existence of these extensions, does it? Let me know your thoughts.

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2014-08-04 06:24:18 -0500 answered a question Multiple network matches found for name 'public-120', use an ID to be more specific.

This happens when you have multiple entries with the same name.

Just replace your network name with the ID.

The Neutron CLI client is smart enough to detect whether it is a name or an ID.

So, your command would look like:

[root@ost-comp-3 ~]# neutron subnet-create <NETWORK-ID> --name public-sub-120 --enable_dhcp=True --allocation-pool start=,end= --dns_nameservers list=true
2014-08-04 05:40:15 -0500 asked a question Running extensions for vendor specific mechanism drivers in ML2


I have a few extensions on my custom monolithic plugin on neutron that I would like to port to work with ML2 when I migrate my plugin to ML2 as a mechanism driver. I understand that Neutron does not currently support extensions for ML2 mechanism drivers ( ), but I would like to know if there are any workarounds possible at the moment.

Thanks in advance for your help!


2014-07-10 05:28:22 -0500 asked a question neutron unit tests creation issues


I'm trying to write a unit test for neutron to verify if port update works if the device_id is specified.

This is what my code looks like:

def test_update_port_id_not_changed(self):
    res = self._create_network(self.fmt, 'net2', True,
    net2 = self.deserialize(self.fmt, res)
    data = {'port': {'admin_state_up': False}}
    res = self._create_port(self.fmt,

    port = self.deserialize(self.fmt, res)
    data = {'port': {'admin_state_up': True,
                     'device_id': port['port']['device_id'],
    res = self._update_port(self.fmt,
    updt_port = self.deserialize(self.fmt, res)
    self.assertEqual(updt_port['port']['admin_state_up'], True)

When I run the test though, I see it failing with the following error:

FAIL: neutron.tests.unit.test_db_plugin.TestPortsV2XML.test_update_port_id_not_changed
_StringException: Empty attachments:

pythonlogging:'': {{{
2014-07-10 14:50:58,200     INFO [neutron.manager] Loading core plugin: neutron.db.db_base_plugin_v2.NeutronDbPluginV2
2014-07-10 14:50:58,421    ERROR [neutron.api.extensions] Extension path 'unit/extensions' doesn't exist!
2014-07-10 14:50:58,506     INFO [neutron.api.v2.resource] create failed (client error): Network a07487d3-b026-4bf5-944e-553584751904 could not be found

pythonlogging:'neutron.api.extensions': {{{2014-07-10 14:50:58,421    ERROR [neutron.api.extensions] Extension path 'unit/extensions' doesn't exist!}}}

Traceback (most recent call last):
  File "/home/mithil/neutron/neutron/tests/unit/", line 1118, in test_update_port_id_not_changed
  File "/home/mithil/neutron/neutron/tests/unit/", line 366, in _create_port
    self.assertEqual(port_res.status_int, expected_res_status)
  File "/home/mithil/neutron/.venv/local/lib/python2.7/site-packages/testtools/", line 321, in assertEqual
    self.assertThat(observed, matcher, message)
  File "/home/mithil/neutron/.venv/local/lib/python2.7/site-packages/testtools/", line 406, in assertThat
    raise mismatch_error
MismatchError: 404 != 201

Could you please tell me what I am doing wrong here? I'm not familiar with writing unit tests, and any pointers would greatly help.



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2014-06-17 05:46:40 -0500 edited question vm can't ping external network

Hi, Trying to get openstack to work, installed RDO with 3 nodes (controller, network, compute) the vm can't reach the internet.

eth0 is the management in my campus network (native vlan).
eth1 is set as trunk ports with vlan's 10,11,20 allowed.
eth2 is the external.
I have created a vlan for it (external) in my campus network for floating ip's and public network for openstack (the vlan id is 20).

[root@controller ~(keystone_admin)]# neutron net-show private
| Field                     | Value                                |
| admin_state_up            | True                                 |
| id                        | 5ed36cac-fb3f-40fc-a897-34b3aa6ce3bc |
| name                      | private                              |
| provider:network_type     | vlan                                 |
| provider:physical_network | physnet1                             |
| provider:segmentation_id  | 10                                   |
| router:external           | False                                |
| shared                    | False                                |
| status                    | ACTIVE                               |
| subnets                   | e4be6c0d-3935-425f-a7fe-b3bc747267f3 |
| tenant_id                 | 3964d2c3ae8e4f20999d06d3b2225c9f     |

[root@controller ~(keystone_admin)]# neutron net-show public
| Field                     | Value                                |
| admin_state_up            | True                                 |
| id                        | c584d431-cae5-456d-bbfe-b23de1c34987 |
| name                      | public                               |
| provider:network_type     | vlan                                 |
| provider:physical_network | physnet1                             |
| provider:segmentation_id  | 11                                   |
| router:external           | True                                 |
| shared                    | False                                |
| status                    | ACTIVE                               |
| subnets                   | 0b3da364-af84-44a5-8f0e-e793fe799802 |
| tenant_id                 | 3964d2c3ae8e4f20999d06d3b2225c9f     |

tcpdump from network node:
17:59:04.353196 ARP, Request who-has tell, length 42
17:59:04.353297 ARP, Reply is-at fa:16:3e:d0:89:c5 (oui Unknown), length 28
17:59:04.936958 ARP, Request who-has tell, length 42
17:59:04.937019 ARP, Reply is-at fa:16:3e:d0:89:c5 (oui Unknown), length 28
17:59:05.353530 ARP, Request who-has tell, length 42
17:59:05.353553 ARP, Reply is-at fa:16:3e:d0:89:c5 (oui Unknown), length 28
17:59:05.940745 ARP, Request who-has tell, length 42
17:59:05.940797 ARP, Reply is-at fa:16:3e:d0:89:c5 (oui Unknown), length 28

tcpdump from compute node:
17:57:58.137333 ARP, Request who-has tell, length 28
17:57:58.725073 ARP, Request who-has tell, length 28
17:57:59.138270 ARP, Request who-has tell, length 28
17:57:59.725488 ARP, Request who-has tell, length 28

but the vm keeps pinging for some reason it does not get the reply or maybe discard it.
what needs to be done in order to gets vm access the internet?

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2014-06-03 11:58:24 -0500 edited question can't connect apche server in instance

I install mutinode openstack in with virtualbox in a ubuntu host( And create new ubuntu instance with floating ip( and fix ip( this instance can connect internet. and I install apche with apt-get install apache2 in this instance. but there is no response when I try to open or with firefox from my ubuntu host(117).

ping successfully from

PING ( 56(84) bytes of data.
64 bytes from icmp_seq=1 ttl=64 time=5.64 ms
64 bytes from icmp_seq=2 ttl=64 time=1.45 ms
2014-06-03 11:56:14 -0500 asked a question How do I add a download button on a custom Horizon panel?

I want this button to be able to fetch a file from a remote server.

I did have a look at , but this just tells me which CSS class to use for my button.

Any pointers would be greatly appreciated.

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2014-04-07 05:27:48 -0500 commented answer Why NEUTRON needs interface phy-br-ex & int-br-ex?

Hey! The flow of packets that you spoke about is for the internal network. There is a similar flow to lead to the external network. VM->qg-XXX->br-int->br-ex->ethX (where ethX is the port that connects to the internet). Note that br-int is also connected to br-eth1 which is your internal network. The veth pair int-br-ex--phy-br-ex connects br-int and br-ex.

2014-04-03 09:22:34 -0500 answered a question Why NEUTRON needs interface phy-br-ex & int-br-ex?

They are virtual ports.

phy-br-ex is the port attached to the vSwitch br-ex and phy-br-int is the port attached to the vSwitch br-int.

These are linked internally to allow traffic to flow from br-ex to br-int, or vice versa. The reason why you cannot see them is because these are taken to be the physical ports through where the traffic flows. Programs like tcpdump only allow you to capture traffic on a driver (eth0, for example).

Hope this helps.

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