From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f45.google.com ([209.85.160.45]:43286 "EHLO mail-pl0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932464AbeCBWjG (ORCPT ); Fri, 2 Mar 2018 17:39:06 -0500 Received: by mail-pl0-f45.google.com with SMTP id f23-v6so6486462plr.10 for ; Fri, 02 Mar 2018 14:39:06 -0800 (PST) Subject: Re: [PATCH net] ipv6: Reflect MTU changes on PMTU of exceptions for MTU-less routes To: Stefano Brivio , "David S . Miller" Cc: Wei Wang , Hideaki YOSHIFUJI , =?UTF-8?Q?Maciej_=c5=bbenczykowski?= , netdev@vger.kernel.org References: <81bfe26bed31319d765a4ebfe86705a49c0a39d5.1520003901.git.sbrivio@redhat.com> From: David Ahern Message-ID: <84593e49-357b-818c-79c5-d265d8c32b03@gmail.com> Date: Fri, 2 Mar 2018 15:39:03 -0700 MIME-Version: 1.0 In-Reply-To: <81bfe26bed31319d765a4ebfe86705a49c0a39d5.1520003901.git.sbrivio@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org List-ID: On 3/2/18 8:36 AM, Stefano Brivio wrote: > Currently, administrative MTU changes on a given netdevice are > not reflected on route exceptions for MTU-less routes, with a > set PMTU value, for that device: > > # ip -6 route get 3000::b > 3000::b from :: dev vti_a proto kernel src 3000::a metric 256 pref medium > # ping6 -c 1 -q -s10000 3000::b > /dev/null > # ip netns exec a ip -6 route get 3000::b > 3000::b from :: dev vti_a src 3000::a metric 0 > cache expires 571sec mtu 4926 pref medium > # ip link set dev vti_a mtu 3000 > # ip -6 route get 3000::b > 3000::b from :: dev vti_a src 3000::a metric 0 > cache expires 571sec mtu 4926 pref medium > # ip link set dev vti_a mtu 9000 > # ip -6 route get 3000::b > 3000::b from :: dev vti_a src 3000::a metric 0 > cache expires 571sec mtu 4926 pref medium Addresses in the 2001:db8: range should be used for commit messages. And please codify the above expectation as a test under tools/testing/selftests/net