From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.33) id 1BeSaG-0008Q3-6G for qemu-devel@nongnu.org; Sun, 27 Jun 2004 01:52:08 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.33) id 1BeSaE-0008OL-Du for qemu-devel@nongnu.org; Sun, 27 Jun 2004 01:52:07 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1BeSaD-0008OI-KY for qemu-devel@nongnu.org; Sun, 27 Jun 2004 01:52:06 -0400 Received: from [130.136.10.114] (helo=pob.cs.unibo.it) by monty-python.gnu.org with esmtp (Exim 4.34) id 1BeSYM-000570-UN for qemu-devel@nongnu.org; Sun, 27 Jun 2004 01:50:11 -0400 Date: Sun, 27 Jun 2004 07:21:32 +0200 Subject: Re: [Qemu-devel] replies Message-ID: <20040627052132.GA14931@cs.unibo.it> References: <20040626184535.GA19123@jbrown.mylinuxbox.org> <200406271007.11404.a_mulyadi@telkom.net> <20040627050111.GA24787@jbrown.mylinuxbox.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040627050111.GA24787@jbrown.mylinuxbox.org> From: renzo@cs.unibo.it (Renzo Davoli) Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org > I don't know why qemu uses "tunX". You'd think it would be better off using the > "tapX" device instead. "tunX" is like "tapX" only it is point-to-point (no > ethernet frames). tun is meant for ip tunnelling and passes ip frames while > tap is for ethernet tunnelling. > > If I understand right tunX will only support ip (and tcp/ip and udp/ip and etc) > while tap also supports ipx, ipv6, etc. Not 100% sure on this point. renzo could > probably answer better on this than I could. Tap would be the more appropriate as entire packets with data-link header are exchanged. > > > > > 2. Can I do traffic shaping / policing against TUN/TAP device attached to Qemu > > guest system? And if I can do it, should I attach the shaper against tun/tap > > or vde switch? > > VDE does not handle traffic shaping/filtering. It is an emulated Ethernet with switches and cables. Consistently with the real world counterpart it is not its role to do that. You can do filtering/shaping on the linux box that works as a router. Tap0 for it is a standard interface thus all the iptables options can be applied. > I am leaving for a conference. Dunno how frequently I'll be able to read my mail and answer.... If you have spare time and need something to read for the sleep instead of counting jumping sheeps, I have published a techreport on VDE (no commands, philosophy only, what you can do with it) http://www.cs.unibo.it/techreports/2004/2004-12.pdf ciao renzo