[Simh] VAX networking issue

[Mark Pizzolato]

On Thursday, June 6, 2019 at 1:53 PM, Zane Healy wrote:
> I have a SIMH/VAX install that was on a Raspberry Pi2 until we had a power
> outage, now the RPi won’t recognize the SD card.  So I’m trying to migrate it to a
> VM (Ubuntu 16.04LTS).  It doesn’t seem to find the network.  I’m able to SSH to
> the host VM, so I know it’s on the network.  I’ve tried both the SIMH available
> for Ubuntu (v3.8), and current.  Of course this is the host with the Quorum disk
> for my Cluster.
> 
> *** vax Simulator being built with:
> *** - compiler optimizations and no debugging support. GCC Version: 5.4.0.
> *** - dynamic networking support using Linux provided libpcap components.
> *** - Local LAN packet transports: PCAP TAP NAT(SLiRP)
> *** - Per simulator tests will be run.
> ***
> *** git commit id is 53ad66f57ebdec051d3345d5957a69707ddc3e32.
> *** git commit time is 2019-06-04T00:02:17-07:00.
> 
> 
> XQ      address=20001920-2000192F, no vector, BR4, MAC=AA:00:04:00:95:F2
>         type=DELQA-T, mode=DELQA, polling=disabled, sanity=OFF
>         throttle=disabled, DEQNALock=OFF, leds=(ON,ON,ON)
> 

The above output is suspicious since it doesn't say that the XQ device has been 
attached to any interface.

What is the output of SHOW ETHER on this simulator?
Are you running as ROOT (which is required for network functionality on Linux unless you are using VDE Ethernet)?
Is the VM Hypervisor you're running under configured to pass arbitrary MAC addresses out of that VM?

Apart from these considerations relating to basic packet capabilities, once you have any networking functionality, you may encounter a problem that has been reported on some Linux systems.  You're not encountering this now, but if you do, you should add the following line to your configuration file:
	sim> SET CLOCK NOCATCHUP

The problem that is not always observed will be fixed soon and the SET CLOCK NOCATCHUP will no longer be necessary.

- Mark