Re: [Qemu-devel] Connecting vde and LAN

["Jim C. Brown" <jma5@umd.edu>]

On Sun, Jul 10, 2005 at 06:42:30PM +0200, Henrik Nordstrom wrote:
> On Sun, 10 Jul 2005, Oliver Gerlich wrote:
> 
> >what is the best solution to connect the vde "switch" to my real LAN so
> >that Qemu guests get IPs from my LAN-wide DHCP server?
> 
> bridgeing of your ethernet interface and the TAP interface connecting to 
> vde is undoubtly the best if you want to provide full access to the LAN.
> 
> >Also I tried to set up IP forwarding between tap0 and eth0, but then the
> >Qemu guests aren't transparently on my LAN (and don't get the correct
> >config from the DHCP server).

The best solution is to use a vde_switch with libpcap and libnet. This allows
intercepting packets meant for the guests (via libnet) and forwarding them thru
vde. libpcap allows for packets in vde to be passed on to the lan. This also
allows for a sort of seamless bridging between host and guest lan. (Technically
a tap device is still required to be able to talk to the host, but my understanding
is that libpcap handles this automatically.) Plus, the nic remains eth0.

I am not sure how libpcap and libnet would work with DHCP or ARP, but since
they work on the ethernet level I suppose a single dhcpd server on eth0 would
work in this case, but I am not 100% sure.

-- 
Infinite complexity begets infinite beauty.
Infinite precision begets infinite perfection.