From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Fw: [Bug 14241] New: Promiscuous mode on network slows the network down Date: Mon, 28 Sep 2009 09:52:03 -0700 Message-ID: <20090928095203.66b85207@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Francois Romieu Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:48109 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751992AbZI1QwM (ORCPT ); Mon, 28 Sep 2009 12:52:12 -0400 Sender: netdev-owner@vger.kernel.org List-ID: Begin forwarded message: Date: Sat, 26 Sep 2009 23:34:40 GMT From: bugzilla-daemon@bugzilla.kernel.org To: shemminger@linux-foundation.org Subject: [Bug 14241] New: Promiscuous mode on network slows the network down http://bugzilla.kernel.org/show_bug.cgi?id=14241 Summary: Promiscuous mode on network slows the network down Product: Networking Version: 2.5 Kernel Version: 2.6.31 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: IPV4 AssignedTo: shemminger@linux-foundation.org ReportedBy: mwahal@gmail.com Regression: No Hi, I have been running 2.6.22.14 kernel for about 2+ years on a pentium D 925, 1GB DDR2 system. I have a realtek 8169 gigabit onboard network controller on a ubuntu distribution. I wanted to try kvm but it didn't run because the kvm-intel module of 2.6.22 kernel is way too old. So, I upgraded to 2.6.28 (and later to 2.6.31 to eliminate 2.6.28 issues) to try that kernel. The kvm did work with 2.6.28. I had to put the ethernet in bridge mode so that the kvm guest OS gets the same IP address from my subnet. As a side effect when putting in bridge mode, the ethernet interface also enters promiscuous mode. I made changes in /etc/network/interface file as per ubuntu kvm wiki page to add a bridge interface and add the eth0 to the bridge port. Anyway, I noticed that certain network related tasks were taking too long. I stream video my server using UPnP to my UPnP client. The UPnP client had trouble streaming over a gigabit network inside my home. I was watching a x264 720p movie yesterday and it was freezing on almost each frame. This is all with 2.6.28 (and later upgraded to 2.6.31 latest kernel). If I downgrade back to 2.6.22 kernel, I dont have any issues streaming even a 20Mbps movie. I've a 6Mbps DSL line at home. I run some scripts during the day to get stocks quotes from yahoo. That involves about issues 100 or so wget requests. On a 2.6.22 kernel, that takes about 2-3 mins to complete. On a 2.6.31 kernel it takes about 45-50 mins. Since I didnt change the /etc/network/interfaces file , so when 2.6.22 loads, the ethernet still enters into promiscuous mode. I can run iftop and see that its watching other traffic on my network. So, my conclusion is that there is something drastically change in the ethernet driver when it runs in promiscuous mode between 2.6.22 and 2.6.28 (or 31) which is making it run excruciatingly slow. I'm open to all suggestions for making any changes to my system. I'm willing to offer whatever information is needed from my system if someone is willing to take a look at it. I do need kvm but not the expense of a sloooow network. Thanks for reading so far. -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug. --