unable to access internet on VM using Devstack

asked 2013-12-16 01:35:41 -0500

Ajitpals gravatar image

updated 2014-01-22 15:12:32 -0500

Evgeny gravatar image

Hi All,

I have setup a ubuntu server with devstack running on laptop for first time. The laptop have two connection Ethernet and Wifi. I using Wifi for internet. So in my network interface, it has following configuration [I have given static address to the eth0]

# The loopback network interface
    auto lo
    iface lo inet loopback

    #The primary network interface
    auto wlan0
    iface wlan0 inet static
                wpa-ssid demo
                wpa-psk  demo

     auto eth0
     iface eth0 inet static

I have created a windows 2012 VM, I can ping the machine and can take remote access via assigning floating IP address to it. But the Windows VM have no internet connection.

My Devstack localrc has following configuration


Before this set up, I have implemented the Flat_Interface on wlan0. Everything worked perfectly but once the VM is created, we are not able to ping the laptop. So I have reinstalled the devstack but with Flat_Interface on eth0, still not able to access the internet.

The windows VM ipconfig is

Windows IP Configuration  
Ethernet adapter Ethernet:

   Connection-specific DNS Suffix  . : novalocal
   Link-local IPv6 Address . . . . . : fe80::954:14a2:4bfb:f247%12
   IPv4 Address. . . . . . . . . . . :
   Subnet Mask . . . . . . . . . . . :
   Default Gateway . . . . . . . . . :

Tunnel adapter isatap.novalocal:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : novalocal

Tunnel adapter Teredo Tunneling Pseudo-Interface:

   Connection-specific DNS Suffix  . :
   IPv6 Address. . . . . . . . . . . : 2001:0:9d38:90d7:20bb:17db:f5f4:f3fd
   Link-local IPv6 Address . . . . . : fe80::20bb:17db:f5f4:f3fd%14
   Default Gateway . . . . . . . . . : ::

I have also tried following command to setup default gateway

sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

How can i resolve the following issue?


edit retag flag offensive close merge delete

2 answers

Sort by ยป oldest newest most voted

answered 2014-10-28 22:45:04 -0500

drolfe_au gravatar image


Yeah the nat didn't sound like a good answer to me as the neutron router should be looking after the nat for the network it looks after, as longs as it's been linked to an external network.

my devstack install, ubuntu14.04 , juno

I just needed to add a physical interface into the ovs br_ex

My my 10g interface is call em1 under ubuntu14

    Bridge br-ex
    Port "qg-1fb6b173-12"
        Interface "qg-1fb6b173-12"
            type: internal
    Port br-ex
        Interface br-ex
            type: internal
    Port "qg-1cd63bd8-d2"
        Interface "qg-1cd63bd8-d2"
            type: internal
ovs_version: "2.0.2"

So there isn't a physical interface attached to the external bridge

Changed the em1 interface config to look like below:

auto em1
iface em1 inet manual
up ifconfig $IFACE up
up ip link set $IFACE promisc on
down ip link set $IFACE promisc off
down ifconfig $IFACE down

Then run the below:

sudo ifdown em1
sudo ifup em1
sudo ovs-vsctl add-port br-ex em1

Check the bridge:

Bridge br-ex
    Port "em1"
        Interface "em1"
    Port "qg-1fb6b173-12"
        Interface "qg-1fb6b173-12"
            type: internal
    Port br-ex
        Interface br-ex
            type: internal
    Port "qg-1cd63bd8-d2"
        Interface "qg-1cd63bd8-d2"
            type: internal
ovs_version: "2.0.2"

Confirm it's working from the VM:

stack@enc2-blade01:~$ ssh cirros@
cirros@'s password:
$ uname -a
Linux test1 3.2.0-60-virtual #91-Ubuntu SMP Wed Feb 19 04:13:28 UTC 2014 x86_64 GNU/Linux

$ ping
PING ( 56 data bytes
64 bytes from seq=0 ttl=51 time=8.273 ms
64 bytes from seq=1 ttl=51 time=6.664 ms
64 bytes from seq=2 ttl=51 time=6.458 ms
--- ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 6.458/7.131/8.273 ms

$ id
uid=1000(cirros) gid=1000(cirros) groups=1000(cirros)

$ ifconfig eth0
eth0      Link encap:Ethernet  HWaddr FA:16:3E:08:AF:CA
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::f816:3eff:fe08:afca/64 Scope:Link
          RX packets:614 errors:0 dropped:0 overruns:0 frame:0
          TX packets:419 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:59794 (58.3 KiB)  TX bytes:47489 (46.3 KiB)
edit flag offensive delete link more

answered 2013-12-16 10:25:40 -0500

Ajitpals gravatar image

I had resolved the following problem. I had done the mistake by calling eth0 it should be wlan0

sudo iptables -t nat -A POSTROUTING -o  wlan0 -j MASQUERADE
edit flag offensive delete link more

Get to know Ask OpenStack

Resources for moderators

Question Tools

1 follower


Asked: 2013-12-16 01:35:41 -0500

Seen: 3,453 times

Last updated: Dec 16 '13