From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Robbins Subject: Re: [Bridge] [PATCH] macvlan: add tap device backend Date: Fri, 7 Aug 2009 11:35:48 -0600 Message-ID: References: <1249595428-21594-1-git-send-email-arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Herbert Xu , "Michael S. Tsirkin" , "Fischer, Anna" , bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, "David S. Miller\"" , Or Gerlitz , Edge Virtual Bridging To: Arnd Bergmann Return-path: Received: from mail-pz0-f196.google.com ([209.85.222.196]:48718 "EHLO mail-pz0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753608AbZHGRfs (ORCPT ); Fri, 7 Aug 2009 13:35:48 -0400 In-Reply-To: <1249595428-21594-1-git-send-email-arnd@arndb.de> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Aug 6, 2009 at 3:50 PM, Arnd Bergmann wrote: > This is a first prototype of a new interface into the network > stack, to eventually replace tun/tap and the bridge driver > in certain virtual machine setups. I have some general questions about the intended use and benefits of VEPA, from an IT perspective: In which virtual machine setups and technologies do you forsee this interface being used? Is this new interface to be used within a virtual machine or container, on the master node, or both? What interface(s) would need to be configured for a single virtual machine to use VEPA to access the network? What are the current flexibility, security or performance limitations of tun/tap and bridge that make this new interface necessary or beneficial? Is this new interface useful at all for VPN solutions or is it *specifically* targeted for connecting virtual machines to the network? Is this essentially a bridge with layer-2 isolation for the virtual machine interfaces built-in? If isolation is provided, what mechanism is used to accomplish this, and how secure is it? Does VEPA look like a regular ethernet interface (eth0) on the virtual machine side? Are there any associated user-space tools required for configuring a VEPA? Do you have any HOWTO-style documentation that would demonstrate how this interface would be used in production? Or a FAQ? This seems like a very interesting effort but I don't quite have a good grasp of VEPA's benefits and limitations -- I imagine that others are in the same boat too. Best Regards, Daniel