Re: ssh client_loop send disconnnect from Dom0 -> DomU (NetBSD 10.0_BETA/Xen)

[Matthias Petermann <mp%petermann-it.de@localhost>]

Hi,

On 23.06.23 02:45, RVP wrote:
> So, the server tries to write data into the socket; write() fails with
> errno = EHOSTDOWN which sshd(8) treats as a fatal error and it exits.
> The client tries to read/write to a closed connection, and it too quits.
>
> The part which doesn't make sense is the EHOSTDOWN error. Clearly the
> other end isn't down. Can't say I understand what's happening here. You
> need a Xen guru now, Matthias :)

I will still try the tips from yesterday (long time ping test) and 
collect some more data. And yes - I think only someone with a strong Xen 
background can really help me :-) I will followup as soon I completed my 
recent tests.

> On Thu, 22 Jun 2023, Brian Buhrow wrote:
>
> >       hello.  Actually, on the server side, where you get the "host is 
> > down" message, that is a
> > system error from the network stack itself.  I've seen it when the arp 
> > cache times out and
> > can't be refreshed in a timely manner.
>
> But, does ARP make any sense for Xen IFs? I thought MAC addresses were
> ginned up for Xen IFs...

At the moment, I manually set the MAC adresses for all DomUs in the 
Domain configuration file (at the network interface specification), example:

```
name="srv-net"
type="pv"
kernel="/netbsd-XEN3_DOMU.gz"
memory=512
vcpus=2
vif = ['mac=00:16:3E:00:00:01,bridge=bridge0,ip=192.168.2.51' ]
disk = [

'file:/data/vhd/srv-net_root.img,0x01,rw','file:/data/vhd/srv-net_data1.img,0x02,rw','file:/data/vhd/srv-net_data2.img,0x03,rw','file:/data/vhd/srv-net_data3.img,0x04,rw',
]
```

I have made sure that there are no duplicates of MAC adresses in my 
network. The reason why I had decided to set them manually was to avoid 
accidental duplicates when operating multiple Xen hosts at the same 
network (My understanding is that I in case the mac= paramater is left 
off, Xen tooling decides for a MAC adress from the 00:16:3E... range).

Actually I don't believe this would make a difference - but should I try 
to avoid the manual specification of the mac adress here for a test?

Kind regards
Matthias

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