Re: [Qemu-devel] Question about tun/tap networking

[renzo@cs.unibo.it (Renzo Davoli)]

On Mon, May 03, 2004 at 01:45:04PM +0200, Arne Bernin wrote:
> On Mon, 2004-05-03 at 05:09, Jim C. Brown wrote:
> Hi Jim,
> 
> > I recommend using vde by Renzo Davoli instead of the default tuntap.
> > I am able to network 2 instances of windows 98 (in separate qemu's) and
> > minix 2.0.4 (in a hand-modified bochs). It worked without a hitch, and all
> > the machines are on the same subnet.
Thank you for the advertisement ;-)
> > 
> > You still need forwarding to let the virtual machines see the lan or the
> > internet, however. The plus with vde is that you don't need to set up routing
> > for all these different tunN devices. (I use the Shorewall firewall, and using
> > tun was a pain...vde means I just have to set up routing and masquerading
> > for tap0, instead of for tun0, tun1, tun2, ...)
> > 
> may you tell me how you set up your vde network ? I downloaded vde,
> installed it, bootet 2 qemus (on the same subnet) and tried to ping each
> other... I does not work, but i can ping the host they run on using a
> tap0 device, and see the who-has... arp stuff while running tcpdump on
> tap0. So it would be very interesting how you configured your vde_switch
> qemu setup for multiple machines on the same vde_switch.

start your vde_switch

% vde_switch -daemon

to run qemu with vde you need to compile and install also the vdeq
utility (inside the qemu subdir of vde source code). Then run

% vdeq qemu ......

use all the other parameters for qemu at the end .... (but -n or
user-net obvsly). vdeq sets -tun-fd automatically.

I have coded also a shortcut to run qemu.
If you make a symbolic link of vdeq to vdesomething it runs "something"
so a symlink to vdeqemu let you write

% vdeqemu .....
instead of the previous command.

(if you have several versions of vde as I do, you can have several
symlinks with several suffixes).
> 

Just a final comment to say that I have just released the vde 1.5 with a
bugfix for qemu support (it missed some packets on very fast networks)
and slirp support for the entire vde network.

Fabrice, I have included your bootp mangement (with copyright and thanks
in the man page and in the README, GPL compliant).

ciao
	renzo