From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hajime Tazaki Subject: Re: [PATCH net-next 3/5] ipv6: Stop /128 route from disappearing after pmtu update Date: Sun, 03 May 2015 23:29:55 +0900 Message-ID: References: <1430251387-2942539-1-git-send-email-kafai@fb.com> <1430251387-2942539-4-git-send-email-kafai@fb.com> <20150502232040.GB2731450@devbig242.prn2.facebook.com> <20150503033801.GE2731450@devbig242.prn2.facebook.com> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Cc: netdev@vger.kernel.org, hannes@stressinduktion.org, steffen.klassert@secunet.com, davem@davemloft.net, yangyingliang@huawei.com, shengyong1@huawei.com, Kernel-team@fb.com To: kafai@fb.com Return-path: Received: from shonan.sfc.wide.ad.jp ([203.178.142.130]:55551 "EHLO mail.sfc.wide.ad.jp" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751567AbbECO36 (ORCPT ); Sun, 3 May 2015 10:29:58 -0400 In-Reply-To: <20150503033801.GE2731450@devbig242.prn2.facebook.com> Sender: netdev-owner@vger.kernel.org List-ID: Hi, At Sat, 2 May 2015 20:38:01 -0700, Martin KaFai Lau wrote: > > On Sun, May 03, 2015 at 09:19:47AM +0900, Hajime Tazaki wrote: > > - 'ip -6 r show' at the ping6 sender > > 2001:1::/64 dev sim0 proto kernel metric 256 > > fe80::/64 dev sim0 proto kernel metric 256 > > > > # the results of ip command on receiver side are almost > > similar. > > > > I found that the test uses non-ARP interface between nodes: > > if I changed the interface to 'non-NOARP' NIC, the issue has > > gone away without the revert. > I have given a little more thoughts. With the below partial patch > ruled out and together with a /64 route in your test, > I failed to see how another line change could have broken. > > Can you share some more details on your test and the test uses two nodes (running on ns-3 network simulator with net-next kernel), which is connected via a point-to-point data link: payload is encapsulated by PPP (RFC1661). https://www.nsnam.org/docs/models/html/point-to-point.html so there is no need of neighbor resolution (ARP, NS/NA) on that link (dev->flags has IFF_NOARP and IFF_POINTOPOINT bits). point-to-point node 0 <---------------> node 1 2001:1::1/64 2001:1::2/64 let me know if you need further information. > can you reproduce it with some basic iproute2 commands? I'm going to create a real environment to figure out a minimum-reproducible command set that we can try. do you have any chance to create an interface with IFF_NOARP and IFF_POINTOPOINT (some tunnel device ?) on the latest net-next kernel ? -- Hajime