From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v2] ipv6: addrconf: fix mcast route for GRE devices Date: Thu, 31 Jul 2014 12:06:52 -0700 (PDT) Message-ID: <20140731.120652.225147288366144806.davem@davemloft.net> References: <20140730153503.GJ801478@jupiter.n2.diac24.net> <1406734797-122248-1-git-send-email-equinox@diac24.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, hannes@stressinduktion.org, stephen@networkplumber.org To: equinox@diac24.net Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:49725 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750709AbaGaTGx (ORCPT ); Thu, 31 Jul 2014 15:06:53 -0400 In-Reply-To: <1406734797-122248-1-git-send-email-equinox@diac24.net> Sender: netdev-owner@vger.kernel.org List-ID: From: David Lamparter Date: Wed, 30 Jul 2014 17:39:57 +0200 > GRE devices, for some reason, were coming up with an autoconfigured > address, but no ff00::/8 route in the local table. This breaks any kind > of multicast, in particular OSPFv3, mDNS, - and ND. In fact, IPv6 only > works at all because there is little need for ND on PtP devices. > > Adding any other IPv6 address on the device from userspace would rectify > this issue through inet6_addr_add()/addrconf_add_dev() - and would leave > the route around even if the address was later removed. (This is > probably why this issue was not discovered earlier. AFAICS it has been > there from the beginning, e.g. aee80b5 "generate link local address for > GRE tunnel") > > (Note: multicast is supported on GRE devices of all kinds, including PtP > GRE, P-t-Mcast GRE and NBMA-GRE.) > > Fixes: aee80b54b235 (ipv6: generate link local address for GRE tunnel) > Signed-off-by: David Lamparter > Cc: Hannes Frederic Sowa > Cc: Stephen Hemminger Hannes, are you OK with this version? Please ACK if so. Thanks.