From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Fw: [Bug 84951] New: 8021q: kernel doesn't take into account ethernet header bytes for received packets Date: Mon, 22 Sep 2014 09:01:34 -0700 Message-ID: <20140922090134.3a114531@urahara> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from mail-pa0-f48.google.com ([209.85.220.48]:35317 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754443AbaIVQBm (ORCPT ); Mon, 22 Sep 2014 12:01:42 -0400 Received: by mail-pa0-f48.google.com with SMTP id ey11so5335202pad.35 for ; Mon, 22 Sep 2014 09:01:41 -0700 (PDT) Received: from urahara (static-50-53-65-80.bvtn.or.frontiernet.net. [50.53.65.80]) by mx.google.com with ESMTPSA id fl15sm9719792pdb.92.2014.09.22.09.01.40 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Sep 2014 09:01:41 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: I am inclined to think this is something that is just an incorrect user expectation. Begin forwarded message: Date: Sun, 21 Sep 2014 11:47:22 -0700 From: "bugzilla-daemon@bugzilla.kernel.org" To: "stephen@networkplumber.org" Subject: [Bug 84951] New: 8021q: kernel doesn't take into account ethernet header bytes for received packets https://bugzilla.kernel.org/show_bug.cgi?id=84951 Bug ID: 84951 Summary: 8021q: kernel doesn't take into account ethernet header bytes for received packets Product: Networking Version: 2.5 Kernel Version: 3.16.1 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Other Assignee: shemminger@linux-foundation.org Reporter: g.djavadyan@gmail.com Regression: No Statistics exported by the kernel for received packets on 802.1q subinterfaces don't consider Ethernet header bytes (dst MAC, src MAC, type). Statistics for transmitted packets is not affected. The problem is more prominent on high-speed links (>100Mb/s), as networking tools (nload, iftop, ...) display lower bandwidth utilization (>5Mb/s difference) than a report from neighboring routing device (FreeBSD, Cisco). Also, someone monitoring Linux router interfaces will find that the router generates more information than it receives. Tested on CentOS kernel 2.6.32-431.29.2.el6.x86_64 and vanilla 3.16.1 with drivers: bnx2, atl1c and igb. How to reproduce: 1. Create dot1q subinterfaces on two boxes (vconfig add eth0 4040). 2. Assign IP addresses to subinterfaces. 3. Check the connection using ping. 4. Check the output from ifconfig eth0.4040 or 'cat /sys/class/net/eth0.4040/statistics/rx_{packets,bytes}'. 5. Issue standard 56 byte payload ping using 'ping -c 1 neighboring_ip'. 6. Recheck statistics using step 4. Expected results: Received packets value should increase by 1 and received bytes value should increase by 98. dst MAC - 6 src MAC - 6 ethertype - 2 IP header - 20 ICMP header - 8 ICMP Payload - 56 Total: 98 bytes. Actual results: Received packets value increases by 1 and received bytes value increases by 84 bytes. -- You are receiving this mail because: You are the assignee for the bug.