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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2808EC433EF for ; Mon, 18 Jun 2018 19:09:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C8D342075E for ; Mon, 18 Jun 2018 19:09:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="o7RMmIZM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C8D342075E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=idosch.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936079AbeFRTJb (ORCPT ); Mon, 18 Jun 2018 15:09:31 -0400 Received: from out2-smtp.messagingengine.com ([66.111.4.26]:50935 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935857AbeFRTJ3 (ORCPT ); Mon, 18 Jun 2018 15:09:29 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.nyi.internal (Postfix) with ESMTP id F36FE22210; Mon, 18 Jun 2018 15:09:28 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute3.internal (MEProxy); Mon, 18 Jun 2018 15:09:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=fm3; bh=9jQnvGP9VcV5Oldn/S4vrIfSeNKef l3WLz7yGDYXzhA=; b=o7RMmIZMJhRMJWPW4LeelyNGunTTEbidkU7cp4MFLXfJE ln9smFGugFp5r6iqUo2kRrnIsFBJRkodkfoHBmVfSn+DST7k1DD/4CRsmfKOwj71 ik5aVpbzD8NSG/zTYMwJskIYhN1Jt/3XvT2P4VJQ4lacmfWJpAs/OYqfOhXcw2HM qKrva4BlwjHHnnbgx9GIiqkNg5sZ1CDIOZX6Z4CYssLvnSj2IyF29UK4pRa6gZ2O pNwCTX/GDAomzxqSV/kD5iMTtWrYw1jCf6Ak4irLcIqKO8n/tWdzLmpoJM/JRoXv b+IUwLsHp9C735oR6fmNqYCJ14eSpZRfGqRW8fYPg== X-ME-Proxy: X-ME-Sender: Received: from localhost (unknown [5.29.216.175]) by mail.messagingengine.com (Postfix) with ESMTPA id 37B6D10262; Mon, 18 Jun 2018 15:09:28 -0400 (EDT) Date: Mon, 18 Jun 2018 22:09:26 +0300 From: Ido Schimmel To: valdis.kletnieks@vt.edu Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: 4.14.(44->48) IPv6 RA issue? Message-ID: <20180618190926.GA18065@splinter> References: <35958.1529334166@turing-police.cc.vt.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <35958.1529334166@turing-police.cc.vt.edu> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 18, 2018 at 11:02:46AM -0400, valdis.kletnieks@vt.edu wrote: > So I'm trying to troubleshoot an issue on an OpenWRT/Lede based > router, where IPv6 connectivity totally fails. I've bisected it down to: > > git log --oneline 187da94808a634477b5e5a69109ea0c566dfa64b..73d8a6ab7668173d70adbed45b61be5256c505e > 73d8a6ab7668 (refs/bisect/bad) base-files: fix UCI config parsing and callback handling > e52f3e9b1376 kernel: bump 4.14 to 4.14.48 > 7590c3c58f5e (HEAD) scripts: Replace obsolete POSIX tmpnam in slugimage.pl with File::Temp function > 987900f2de76 hostapd: properly build hostapd-only SSL variants > > and am pretty sure that it's the kernel bump (works with a 4.14.44 kernel, > breaks with 4.14.48) as the other 3 commits don't go anywhere near IPv6 handling. ... > Note that eth1 is the uplink towards my ISP. I've pointed a 'tcpdump -n -i eth1 ip6' > at it, and see plenty of RA packets come in, but neighbor discovery never completes. > Looking at the Changelogs for .45->.50 don't show any smoking-gun patches. > > This ring any bells, before I delve deeper into it? If this is a router and forwarding is enabled, then you need to set 'accept_ra' to '2' [1]. Is this what you have configured? Seems that OpenWRT recently started to explicitly set 'accept_ra' to '0' [2]. 1. https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt 2. https://github.com/openwrt/openwrt/commit/bb46520159c0119e829900e29681feea6f297fe0