[Qemu-devel] About network bridge.

[Yaodong Yang]

Hello everyone,

Thanks for reading my email. I got a question about the network bridge in qemu-kvm.

When I start my vm using virsh start vm2 or virt-manager, the vm's network is working. I can access the internet within the vm. 

However, we I start the same vm using qemu-system-x86_64 vm2.img -m 1024. The vm can run but without internet access. I do not know the reason, can someone give me a direction?

The procedure to set up the system.

1. install the host os, set up bridge networking.

2. use virt-manager create guest vm, choose bridge network in the creation option of virt-manager.

3. run the guest vm.

My system configuration is as follows:

1. Host OS, Ubuntu 12.10 server with a kubuntu-desktop.

2. QEMU-KVM version is 1.2.0.

3. Host network configuration is bridge type, as follows:

# The loopback network interface

auto lo

iface lo inet loopback

# The primary network interface

auto em1

iface em1 inet manual

auto br0

iface br0 inet static

        address 192.168.1.2

        netmask 255.255.255.0

        network 192.168.1.0

        broadcast 192.168.1.255

        gateway 192.168.1.1

        # dns-* options are implemented by the resolvconf package, if installed

        dns-nameservers 129.93.6.189

        bridge_ports em1

        bridge_fd 9

        bridge_hello 2

        bridge_maxage 12

        bridge_stp off

4. Guest OS ubuntu-server 12.10. network configuration is as follows:

auto lo

iface lo inet loopback

# The primary network interface

auto eth0

iface eth0 inet static

        address 192.168.1.12

        netmask 255.255.255.0

        network 192.168.1.0

        broadcast 192.168.1.255

        gateway 192.168.1.1

        # dns-* options are implemented by the resolvconf package, if installed

        dns-nameservers 129.93.6.189

Thanks!

Best,

Yaodong

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Yaodong Yang

Ph.D. Student

Department of Computer Science & Engineering

University of Nebraska-Lincoln 

Email: address@hidden OR address@hidden