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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 88456C433E1 for ; Fri, 14 Aug 2020 07:08:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BF9E20708 for ; Fri, 14 Aug 2020 07:08:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BxNt+9mW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726247AbgHNHIp (ORCPT ); Fri, 14 Aug 2020 03:08:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726006AbgHNHIo (ORCPT ); Fri, 14 Aug 2020 03:08:44 -0400 Received: from mail-lj1-x232.google.com (mail-lj1-x232.google.com [IPv6:2a00:1450:4864:20::232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF948C061757 for ; Fri, 14 Aug 2020 00:08:43 -0700 (PDT) Received: by mail-lj1-x232.google.com with SMTP id i10so8894589ljn.2 for ; Fri, 14 Aug 2020 00:08:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=uPbmn/u6g9gKyCwRFx78Ln8dhwRaKx1gs+n42Nu7NAo=; b=BxNt+9mWfNNJTTzoL96Zv/fvOr+0b0g7nZfiRCjhDAzt7Qpu5g+mMldRmzL4Awajn2 nECkkTFJf7e6iTsXGX0KQ32WKzbuIF6TdM2Ysk3wYjj2MgPHLmAjRZ6+soFtgNkY2VZ5 YxpmtHudzvF1bozOcSmJplwADl/FOHmj29xg+v4VdlzOHRTGciNQ8vrCrvbNu1z9zOgu Lj4Jmb7NIofDSe8POL9odaWmGjy+uFOVbMicN0ljR/iAguaaNxYkDyMflx+/ZO+VgD8g eN528dkI8Npo6sVvWOM/iyVzQ4b+FuV68czcmfk2fPobj5GzEtsRbPMlc7CXDUiyKN+K HLyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=uPbmn/u6g9gKyCwRFx78Ln8dhwRaKx1gs+n42Nu7NAo=; b=pyFpe7bvpMum/HQib2UmLnSVhq7cL2zV1mHzNGMNQwChuuhzYjjxm9ZCO7pvetIGCo snZS3ypwaEX5uxj5tYvccRPwWrMiDxuuASKj356Jw2AURErYSlywImaF4ucKT1fQ5Ppl zZvJ0PK7nhBr5fDI2iJi0TL5MeIGw3JIURNYriqRWrlalOFx+dmBCYiYxFebc2eV1Ubf s9X6jaxHPBWZyD0qnXhMJmmu7mLb7M9yJ7SqgWD1o67KzsgGrlrKtTZSulKfwzESE7sl +Df1MnXwDxtpuAaj5cgA0OtGDG3MaloWyxP+2kgetLQGQojY/yWGgRrufmIbzzTUpBgh AuQg== X-Gm-Message-State: AOAM53002BLsAlz4B6U7RhEDvO7zamuafW0EECaTpYrP+HwsBZDPToyX QqwPuA8gvVognQlVoT4sUbfa1+lISDTSWAqHCFA= X-Google-Smtp-Source: ABdhPJzm75kAIrlIPs0GNnEHP7yXUoQI3JB623nqPUcxrWEZvaN8iY7I5jkpHTCTCMopzpXnqeaBkZnfE9UgJNh/+UI= X-Received: by 2002:a2e:8999:: with SMTP id c25mr728879lji.430.1597388921873; Fri, 14 Aug 2020 00:08:41 -0700 (PDT) MIME-Version: 1.0 References: <1b4ebdb3-8840-810a-0d5e-74e2cf7693bf@gmail.com> <962617e5-9dec-6715-d550-4cf3ee414cf6@gmail.com> In-Reply-To: <962617e5-9dec-6715-d550-4cf3ee414cf6@gmail.com> From: mastertheknife Date: Fri, 14 Aug 2020 10:08:30 +0300 Message-ID: Subject: Re: PMTUD broken inside network namespace with multipath routing To: David Ahern Cc: netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hello David, It's on a production system, vmbr2 is a bridge with eth.X VLAN interface inside for the connectivity on that 252.0/24 network. vmbr2 has address 192.168.252.5 in that case 192.168.252.250 and 192.168.252.252 are CentOS8 LXCs on another host, with libreswan inside for any/any IPSECs with VTi interfaces. Everything is kernel 5.4.44 LTS I wish i could fully reproduce all of it in a script, but i am not sure how to create such hops that return this ICMP Thank you, Kfir On Wed, Aug 12, 2020 at 10:21 PM David Ahern wrote: > > On 8/12/20 6:37 AM, mastertheknife wrote: > > Hello David, > > > > I tried and it seems i can reproduce it: > > > > # Create test NS > > root@host:~# ip netns add testns > > # Create veth pair, veth0 in host, veth1 in NS > > root@host:~# ip link add veth0 type veth peer name veth1 > > root@host:~# ip link set veth1 netns testns > > # Configure veth1 (NS) > > root@host:~# ip netns exec testns ip addr add 192.168.252.209/24 dev veth1 > > root@host:~# ip netns exec testns ip link set dev veth1 up > > root@host:~# ip netns exec testns ip route add default via 192.168.252.100 > > root@host:~# ip netns exec testns ip route add 192.168.249.0/24 > > nexthop via 192.168.252.250 nexthop via 192.168.252.252 > > # Configure veth0 (host) > > root@host:~# brctl addif vmbr2 veth0 > > vmbr2's config is not defined. > > ip li add vmbr2 type bridge > ip li set veth0 master vmbr2 > ip link set veth0 up > > anything else? e.g., address for vmbr2? What holds 192.168.252.250 and > 192.168.252.252