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I have been experimenting with LXC virtualisation in order to run virtual machines on a dedicated server, but am having trouble setting up the networking properly.

I am using veth bridged networking, as instructed here: (the guide I used to setup the LXC container)

When I start the container, it functions fine, can access the Internet and accepts incoming connections to it's own IP. However, as soon as I start it, the networking on my host box (dedicated server) goes down completely, and will not come back until the server is rebooted.

The only thing I can think of that would be causing this is incorrectly configured bridging settings, however I'm not sure entirely what the proper ones should be. Any advice on how I could reconfigure this? Thanks.

Both the host node and the container itself are running Debian Squeeze, with packages upgraded to the latest versions.

Host node (dedicated server) network configuration (/etc/network/interfaces):

allow-hotplug eth0
auto br0
iface br0 inet static
    bridge_ports eth0
    bridge_fd 0
    bridge_stp off
    bridge_maxwait 0 

LXC container network configuration (/etc/network/interfaces):

auto eth0
iface eth0 inet static
    post-up route add dev eth0
    post-up route add default gw
    post-down route del dev eth0

Container network configuration (from LXC config file):

lxc.utsname = paradox = veth = up = br0 = 02:00:00:ba:47:a0 =
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migrated from Sep 21 '12 at 15:57

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This is not exactly an answer, but have you checked out docker? It dramatically simplifies the process of working with Linux containers. I have also had more success using libvirt to manage containers (virsh -c lxc:/// ...) than using the native lxc-* toolset. –  larsks Aug 4 '13 at 0:21

2 Answers 2

Seems you re-plug your adapter. ..

Do you have an apater on the dedicated server that is connected to the bridge? I would be curious, what happens if you start a second container?

Instead of routing with words involved like dev and eth0, I might would like to take a look at someting to manage the virtual networks, especially if you would be also OK with a NAT solution. Did you took at livbvirt?

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I created many squeeze/wheezy containers by the same instruction (

The only thing I do different way is that I use a virtual network bridge. (And I think the problem is that you have a bridge to your network card, not to a virtual device)

Add something like this to your /etc/network/interfaces (using your own numbers):

auto eth0.5
iface eth0.5 inet manual
  vlan_raw_device eth0

auto vzbr5
iface vzbr5 inet static
  bridge_maxwait 0
  bridge_ports none
  post-up /usr/sbin/brctl addif vzbr5 eth0.5
  post-up /sbin/ifconfig eth0.5 up


sudo ifup vzbr5

After that use vzbr5 as a network device.

Please see the complete instruction.

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Adding the instructions would improve this answer. Links can and do break. –  Dave M Oct 1 '13 at 14:32
@DaveM Thanks for your advice. –  Sergei Lodyagin Oct 1 '13 at 18:50

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