Re: [Qemu-devel] How to make TCP/IP applications run on guest OS?

[Stefan Hajnoczi]

On Wed, Dec 19, 2012 at 09:54:32PM +0800, GaoYi wrote:
> Hi all,
> 
>    I have bridged the network of the host. There was one br0 and several
> taps on it. When I started up a guest using:
> 
>                      #kvm -hda ubuntu.img -localtime -m 1G  -net nic, -net
> tap,ifname=tap0,script=no
> 
>    The guest can ping to other VMs or physical PCs within the same LAN.
> However, when I tried to communicate with other VMs/PCs using TCP/IP,
> the incoming IP at the receiver side is the same as the host IP instead of
> the VM's IP. Then how to configure the network so that
> the TCP/IP applications run well just like the phsical PC?

libvirt/virt-manager can set up the network for you.  I suggest using
them if you're having issues configuring bridging.

There is some basic information here but you'll find specifics if you do
a web search for "qemu bridging" or similar:
http://wiki.qemu.org/Documentation/Networking

Stefan