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User-agent: mu4e 1.3.5; emacs 26.3
From: Nico Schottelius <nico.schottelius@ungleich.ch>
To: Daniel Corbe <daniel@corbe.net>
Cc: alpine-user@lists.alpinelinux.org
Subject: Re: IPv6 Forwarding Troubles
In-reply-to: <CAMxLOn0vRkynO7tDD=jdOm6MaF2Ecn-b1Q+9-eLJnYd2K4ERvw@mail.gmail.com>
Date: Sat, 07 Dec 2019 19:04:24 +0100
Message-ID: <87h82cnhav.fsf@ungleich.ch>
MIME-Version: 1.0
Content-Type: text/plain


Hey Daniel,

that is correct. The sysctl that you are looking for is accept_ra=2.

Best,

Nico

p.s.: Fell for this many, many times before...

Daniel Corbe <daniel@corbe.net> writes:

> Hello All,
>
> I'm seeing strange behavior inside an Alpine Linux VM.
>
> I'm trying to enable IPv6 forwarding via sysctl.  In its default
> configuration, Alpine is getting an IPv6 address and a gateway and I'm
> able to ping6 www.google.com
>
> I have neighbors:
>
> # ip -6 neigh show
> fe80::fc00:2ff:fe73:a13e dev eth0 lladdr fe:00:02:73:a1:3e router used
> 0/0/0 probes 1 STALE
>
> I have a default gateway:
>
> # ip -6 route list
> 2001:19f0:9002:1c2f::/64 dev eth0  metric 256  expires 0sec
> fe80::/64 dev eth0  metric 256
> default via fe80::fc00:2ff:fe73:a13e dev eth0  metric 1024  expires 0sec
> ff00::/8 dev eth0  metric 256
>
> When I do this:
>
> # sysctl -w net.ipv6.conf.all.forwarding=1
>
> I lose my default gateway:
>
> # ip -6 route list
> 2001:19f0:9002:1c2f::/64 dev eth0  metric 256  expires 0sec
> fe80::/64 dev eth0  metric 256
> anycast 2001:19f0:9002:1c2f:: dev eth0  metric 0
> anycast fe80:: dev eth0  metric 0
> ff00::/8 dev eth0  metric 256
>
> Now I no longer have any IPv6 connectivity.  Can anyone point me in
> the right direction here?


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