Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have installed openstack (packstack) on centos 6.4 with neutron. The openstack is installed on single virtual machine using vmware.

First i have created external network using following command

quantum net-create public --router:external=True

Then i added my external network subnet (ip pool not used in external network)

Then i created router

Then i set my router gateway to external network

I created security group to allow ssh and icmp.

On second step i created private network with dhcp enabled

Then created router interface and attach it to my private network

On third step i launched the instance with private network

On fourth step i generated floating ip of external network and associates it to instance

Problem Statement:

Virtual machines are getting IP's (private network) from dhcp and communicating with each other but there is No internet on VM's

VM's cannot ping any external network device.

I am using Centos 6.4. Ip route shows dev eth1 proto kernel scope link src metric 1 dev virbr0 proto kernel scope link src dev br-ex proto kernel scope link src dev eth0 scope link metric 1002 dev br-ex scope link metric 1017

default via dev br-ex

Where is my external network on eth0 (for internet) is my anoother interface on eth1

quantum agent-list shows ----+-------+----------------+

| id | agent_type | host | alive | admin_state_up |


| 4c709a4c-bf0c-4e03-a0f5-2d938fee7ae1 | L3 agent | localhost.localdomain | :-) | True |

| 960a7806-dc4d-4ab1-99b0-a79dbc31600f | Open vSwitch agent | localhost.localdomain | :-) | True |

| d9f545e2-4a6c-43f4-8037-b807cbe27fc5 | DHCP agent | localhost.localdomain | :-) | True |


share|improve this question
I'm pretty sure you need to enable Promiscuous Mode on the vSphere vSwitch port group in order for nested hypervisor VM's to have access to the network. – joeqwerty Sep 28 '13 at 13:58
I am using vmware workstation 8 for Windows. I think Promiscuous Mode is available for vmware linux platforms only. – Zain Ali Mughal Sep 28 '13 at 14:08
Well then you're probably out of luck. – joeqwerty Sep 28 '13 at 14:11

So you have created a VMWare Virtual Server, and in this VM, installed OpenStack, which itself hosts VMs?

Then the Virtual Switch the VMWare VM is connected to, blocks every traffic from your OpenStack VMs. This is a security measure, to make sure only VMWare VMs can reach the Virtual Switch and the outside network. This is a layer 2 trouble, I am quite sure the arp -an command in OpenStack VMs does not show you gateway.

All you have to do is allow the VMWare Virtual Switch to receive multiple MAC addresses.

You can find how to do this onthis post


I don't know. What I think I know, is that you can't reach you router, and as consequence, the outside network, even at a Layer 2 (check for this that no MAC address is shown for the gateway when launching the arp -an command) because the VSwitch is dropping paquets whom mac-addresses are not those of the OpenStack server.

Then, you can either disabled this feature in the VSwitch, or install on your OpenStack server an ARP-proxy service. The idea is to spoof MAC-address of your VMs which will then appear on the VSwitch as the OpenStack server itself.

share|improve this answer
Thanks for your response. iam reading the post mean while can u please tell me "ip netns-list" is not showing qrouter although l3 agent is installed. why ? – Zain Ali Mughal Sep 28 '13 at 14:16
I have answered your comment in my initial post – philippe Sep 28 '13 at 16:58
I have installed vmware workstation 8 on windows 7, i cannot find the options that you have recommended in your post (on the VMware host, configuration, networking, select the vswitch your lxc-host is connected to, properties, Edit, security, MAC address changes -> Accept ) – Zain Ali Mughal Sep 28 '13 at 18:22
You need to use VMware vSphere Client on Windows as VMware Workstation allows you only to edit VMs parameters and not hosts parameters. – philippe Sep 30 '13 at 11:31

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.