From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ryan Whelan <rcwhelan@gmail.com>
Subject: Re: iproute2 - modifying routes in place
Date: Mon, 14 May 2018 16:10:44 -0400
Message-ID: <CAM3m09SGxsBhxeQoM8GNjMCryUjpMPqon3OYrdO3_FKmp91z3Q@mail.gmail.com>
References: <CAM3m09SxxFRfhssnj9k21D=PVfJ-yRx7P2DnfpLK2C4QHvcrtQ@mail.gmail.com>
 <07d96b60-68e5-8c20-8505-3df9178f9f78@gmail.com> <CAM3m09SowB_i7eoC4FGH=gYBoYRTdBO5S4paVdJ4Mb1RtYfe=A@mail.gmail.com>
 <7b4fac83-210f-2e91-5e56-6a381bd2a5ba@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Cc: netdev@vger.kernel.org
To: David Ahern <dsahern@gmail.com>
Return-path: <netdev-owner@vger.kernel.org>
Received: from mail-qt0-f182.google.com ([209.85.216.182]:41993 "EHLO
        mail-qt0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1751855AbeENUKz (ORCPT
        <rfc822;netdev@vger.kernel.org>); Mon, 14 May 2018 16:10:55 -0400
Received: by mail-qt0-f182.google.com with SMTP id c2-v6so17870855qtn.9
        for <netdev@vger.kernel.org>; Mon, 14 May 2018 13:10:55 -0700 (PDT)
In-Reply-To: <7b4fac83-210f-2e91-5e56-6a381bd2a5ba@gmail.com>
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>

On Mon, May 14, 2018 at 2:49 PM David Ahern <dsahern@gmail.com> wrote:

> On 5/14/18 12:40 PM, Ryan Whelan wrote:
> > Same behavior:
> >
> >
> > root@rwhelan-linux ~
> > # ip -6 route
> > ::1 dev lo proto kernel metric 256 pref medium
> > fd9b:caee:ff93:ceef:3431:3831:3930:3031 dev internal0 proto kernel
metric
> > 256 pref medium
> > fd9b:caee:ff93:ceef:3431:3831:3930:3032 dev internal0 src
> > fd9b:caee:ff93:ceef:3431:3831:3930:3031 metric 1024 pref medium
> > fe80::/64 dev enp0s3 proto kernel metric 256 pref medium
> > fe80::/64 dev enp0s8 proto kernel metric 256 pref medium
> > fe80::/64 dev internal0 proto kernel metric 256 pref medium
> >
> > root@rwhelan-linux ~
> > # ip -6 route change fd9b:caee:ff93:ceef:3431:3831:3930:3032 dev
internal0
> > src fd9b:caee:ff93:ceef:3431:3831:3930:3031 metric 10
> > RTNETLINK answers: No such file or directory

> 'change' only sets NLM_F_REPLACE. Since NLM_F_CREATE is not set ('ip ro
> replace') it does not add a new route and expects one to exist. Your
> table above shows the prefix with metric 256 not metric 10 so the route
> does not match. You should be seeing a message in dmesg to this effect.


Is there a syntax for changing a route in-place?  Specifically, i'm
interesting in changing the metric of currently existing routes.