[systemd-devel] IPv6 forwarding inside systemd-nspawn containers

[Egor M.]

Hello Lennart.

In this case there's a slight inconsistence somewhere since net.ipv4.ip_forward
setting is inherited from host but net.ipv6.conf.all.forwarding isn't. One way
or another, remounting /proc/sys r/w seems to be helping. I'll do more tests on
Monday and see if everything's fine. Thank you!

On Fri, Jun 10, 2016 at 03:18:10PM +0200, Lennart Poettering wrote:
> On Thu, 09.06.16 17:11, Egor M. (dsx+systemd-devel at droidnest.org) wrote:
> 
> > Hello.
> > 
> > How to enable IPv6 forwarding in systemd-nspawn containers? I have a container
> > with network-bridge (--network-bridge=br0). Despite of
> > net.ipv6.conf.all.forwarding value and corresponding interface values, IPv6
> > forwarding is still disabled inside container, while IPv4 forwarding inherited
> > correctly from host system and works just fine.
> 
> Hmm, did I grok this right, you want to enable IPv4 forwarding inside
> the container, so that the container acts as router?
> 
> Currently npsawn will mount all of /proc/sys read-only, under the
> assumption that these sysctl are not namespaced. Are you saying the
> networking controls are correctly namespaced, and thus can be set to
> different values from the host without interfering with it? If so, we
> should probably mount /proc/sys/net writable after all.
> 
> If so, could you please file a PR about this, and we'll make the
> change in upstream nspawn.
> 
> For now though you can just make /proc/sys/net writable manually and
> then set the right sysctl there...
> 
> Lennart
> 
> -- 
> Lennart Poettering, Red Hat

-- 
Egor M.