From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAE6BC433F5 for ; Thu, 17 Feb 2022 02:59:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232169AbiBQDAI (ORCPT ); Wed, 16 Feb 2022 22:00:08 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:35754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232102AbiBQDAG (ORCPT ); Wed, 16 Feb 2022 22:00:06 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9B2CD1FFF46; Wed, 16 Feb 2022 18:59:53 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 37E4161D00; Thu, 17 Feb 2022 02:59:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21AF0C004E1; Thu, 17 Feb 2022 02:59:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645066792; bh=Cc8p4juRyZDLDiYHYoHlaCKkmOjUBJrr6ymTfTTrnJw=; h=Date:Subject:To:References:From:In-Reply-To:From; b=oTA2x1m/1tJy/0RO1pN30NJa2BJkYMh2+KKMBKb1RwI/36S8e7LFjr4cNM021ZjLH rrHPNICPqWSAYYOTpTZx0MN3UuCUGdqTVOnYlO2LxFqkOTRQjRtlJo5jKoL1vdyhuz EdJpo9K/NzhCRDGu96UxhRlCUDYofEMAeXkFI10rCODhdq1mb/y+HsydVx9J8xod5N lISmjXwtlOqdPHYFGZHJl/flAwwv26jxJX1NsM1eLJRwa4fWq98mH7tgia0DdM1TRy +bUzGU61/pEWnf95B0p4saetWhWzaAG4JPlTsEdOUQ8A3ICnTpU7hSm/vpss90L4iT oWCBf8lCv7wuw== Message-ID: Date: Wed, 16 Feb 2022 19:59:50 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.6.0 Subject: Re: This counter "ip6InNoRoutes" does not follow the RFC4293 specification implementation Content-Language: en-US To: "Xiao, Jiguang" , "davem@davemloft.net" , "yoshfuji@linux-ipv6.org" , "kuba@kernel.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: From: David Ahern In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/16/22 3:36 AM, Xiao, Jiguang wrote: > Hello, > > I found a counter in the kernel(5.10.49) that did not follow the RFC4293 > specification. The test steps are as follows: > >   > > Topology: > >   |VM 1| ------ |linux| ------ |VM 2| > >   > > Steps: > > 1. Verify that “VM1” is reachable from “VM 2” and vice versa using ping6 > command. > > 2. On “linux” node, in proper fib, remove default route to NW address > which “VM 2” resides in. This way, the packet won’t be forwarded by > “linux” due to no route pointing to destination address of “VM 2”. > > 3. Collect the corresponding SNMP counters from “linux” node. > > 4. Verify that there is no connectivity from “VM 1” to “VM 2” using > ping6 command. > > 5. Check the counters again. > >   > > The test results: > > The counter “ip6InNoRoutes” in “/proc/net/dev_snmp6/” has not increased > accordingly. In my test environment, it was always zero. > >   > > My question is : > > Within RFC4293, “ipSystemStatsInNoRoutes” is defined as follows: > >   “The number of input IP datagrams discarded because no route could be > found to transmit them to their destination.” > > Does this version of the kernel comply with the RFC4293 specification? > >   I see that counter incrementing. Look at the fib6 tracepoints and see what the lookups are returning: perf record -e fib6:* -a Ctrl-C perf script