From mboxrd@z Thu Jan  1 00:00:00 1970
From: Georgios Amanakis <gamanakis@gmail.com>
Date: Fri, 03 Jun 2016 01:38:34 +0000
Subject: ip6tables --set-mark drops/distorts link-local packets
Message-Id: <1464917914.16925.15.camel@gmail.com>
List-Id: <lartc.vger.kernel.org>
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To: lartc@vger.kernel.org

Hi all,

I discovered that marking IPv6 packets with ip6tables results in link-
local traffic being dropped/distorted. Specifically link-local UDP
traffic on ports 546-547 (necessary for DHCPv6) fails in this
situation. I provide a script for testing purposes:

-----------8<------------
#!/usr/bin/sh

ip6tables -t mangle -F=C2=A0
ip6tables -t mangle -A OUTPUT -o $oif -j MARK --set-mark 3

exit 0
-----------8<------------

Is this behavior known/expected? My search didn't reveal any relevant
results on the web.
I am running Archlinux, uname -a:
"Linux a-router 4.4.11-1-lts #1 SMP Thu May 19 21:03:24 CEST 2016
x86_64 GNU/Linux"

George