sshd 7.8p1 close connection from VMware Fusion NAT Port Forwarding

[Job Snijders]

On Tue, 28 Aug 2018 at 06:24, Damien Miller <djm at mindrot.org> wrote:

> On Mon, 27 Aug 2018, Stuart Henderson wrote:
>
> > On 2018-08-27, Zach Cheung <kuroro.zhang at gmail.com> wrote:
> > > After upgrading my VMware Fusion (10.1.3) Arch Guest to the latest with
> > > OpenSSH upgraded from 7.7p1 to 7.8p1, found that ssh from macOS Sierra
> > > (10.12.6) host to Arch guest via local NAT port forwarding failed, but
> via
> > > Arch LAN IP worked, downgraded OpenSSH from 7.8p1 to 7.7p1 fixed the
> > > problem.
> > >
> > > Any idea about this bug?
> >
> > I bet it is the QoS change. Try "IPQoS lowdelay,throughput".
>
> Do you have any insight into what is breaking here? I don't believe
> changing the default DSCP values should break connections...



I suspect VMWare Fusion has a very broken NAT implementation, where they
seem to hash packets to identify flows on (part of) the DSCP field.

Kind regards,

Job