[Simh] Raspberry Pi 3 with tun/tap causes XQ to fail

[paulhardy2 at btinternet.com]

A couple of points:

1)  The ?53 self test error might be a red herring – I intermittently get ?53 2 errors on both Windows (Intel) and Raspbian (pi 3) when starting the VAX emulation under SIMH. I think it is something to do with the clock test failing, because the emulation is sufficiently fast that the test that the clock is advancing fails because it hasn’t yet ticked during the test. Despite the message saying normal operation not possible, if you try and boot VMS, it works fine.

2) I successfully boot my raspberry pi into my VMScluster (boot node is SimH on Windows) without any faffing with tun/tap/br. I just ATTACH XQ ETH0, and my Simh satellite happily boots from  XQ. I realise that I might need more infrastructure if I needed local routing from VAX to host (without echo from a physical ethernet switch), but for normal VMS operation in a cluster, it works fine without.

 

Regards,

 

From: Simh [mailto:simh-bounces at trailing-edge.com] On Behalf Of Jeremy Begg
Sent: 13 November 2017 13:17
To: Wilm Boerhout <wboerhout at gmail.com>
Cc: simh at trailing-edge.com
Subject: Re: [Simh] Raspberry Pi 3 with tun/tap causes XQ to fail

 

Hi Wilm,

 

Thanks for the clarification :-)

I had already worked out the changes to the commands to get the IP setup, but it appears under “stretch” the set of commands in your note are not quite right.

(I realise your example closely matches the SIMH documentation.)

 

HOWEVER, I am pleased to report success!

 

I was reading the blog at https://mansfield-devine.com/speculatrix/2016/03/networking-vax-openvms-on-simh-the-raspberry-pi/ and he produces much the same configuration, with one very important difference: in his system, the tap0 interface is assigned an IP address (in addition to br0).  As soon as I did that, it started working!

 

Perhaps this is specific to raspbian “stretch”?  I notice from several discussion forums that many people are not happy with the networking changes made in this release.

 

Anyway, thanks for your time.

 

Regards,

 

                Jeremy Begg

 

 

On 13 Nov 2017, at 11:13 PM, Wilm Boerhout <wboerhout at gmail.com <mailto:wboerhout at gmail.com> > wrote:

 

Jeremy Begg schreef op 13-11-2017 om 13:38:

Hi Wilm,
 
Thank you for the prompt reply.
 

On 13 Nov 2017, at 9:43 PM, Wilm Boerhout  <mailto:wboerhout at gmail.com> <wboerhout at gmail.com> wrote:
 
Jeremy Begg schreef op 13-11-2017 om 11:03:

Hi,
 
I am trying to get SIMH up and running on the ethernet interface of a
Raspberry Pi 3.  I have followed the intructions in 0readme_ethernet.txt,
installing the libpcap-dev, bridge-utils and uml-utilities packages before
building SIMH itself.  I just ran 'make vax' and let it go, and the build to
completion.
 

[snip]
 
My TUN/TAP and bridge are set up in /etc/rc.local in Raspbian (jessie & stretch), as follows:

Are you sure this applies to the machine running the “stretch” release?
The ‘ifconfig’ command on that system (well, on mine, anyway!) doesn’t display “inet addr” anywhere in its output, it just has “inet”.
So the various grep commands in your example don’t work.
 
Thanks
 
   Jeremy Begg

Oops, my bad. I did not realize that this Pi is the one remaining that still runs jessie. I hate to convert because it doubles as my OpenVPN server.

Anyway, for stretch, the setup is the same, aprt from:

# get current IP params
HOSTIP=`ifconfig $IFACE | grep "inet " | gawk -- '{ print $2 }'`
HOSTNM=`ifconfig $IFACE | grep "inet " | gawk -- '{ print $4 }'`
HOSTBC=`ifconfig $IFACE | grep "inet " | gawk -- '{ print $6 }'`
HOSTGW=`route -n | grep ^0.0.0.0 | gawk -- '{ print $2 }'`

/Wilm

 

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