[Simh] Networking through multiple layers of emulation

[Stephen Hoffman]

On Mon, 09 Nov 2009 14:08:00 +1100, susanmackay at optusnet.com.au posted:

> I'm not sure where to start with my problem so I thought I'd start at the top/bottom (depending on your point of view) and work my way to the other end.
> My situation is:
> - OpenVMS running in simh (v3.8-1 - the version that comes as a "Port" in the FreeBSD distribution)
> - simh running under FreeBSD (DHCP etc working) - V7.2
> - FreeBSD running as a Parallels VM (bridged networking) - latest update of Parallels V4
> - Parallels running on my MacBook Pro using 10.6 (Snow Leopard) - fully patched
> - wireless network back to a Netgear router that runs the DHCP service

You've never mentioned if you're intending such a long and arduous and complex path from the top of the software stack to the iron, or if you just want to run OpenVMS on simh on your Mac.

If the latter, see <http://labs.hoffmanlabs.com/node/922> for instructions.

> 
> I'm trying to get TCP/IP (UCX) running on the VMS system. I've installed it OK but using the SYS$MANAGER:TCPIP$CONFIG doesn't result in anything that works.
> 
> The FreeBSD system is able to get a proper IP address from the Netgear DHCP "service" so I think everything is OK to that point. Also I can telnet and FTP between the FreeBSD environment and my Mac.
> 
> If I try to configure UCX to use its DHCP client then the TCPIP$CONFIG option to start everything going freezes at the point where the DHCP client tries to get an IP address.

I recommend against using DHCP with OpenVMS in all but the simplest and client-oriented cases.  Yes, DHCP is an option and yes it (mostly) works.  Sort of.  But I've usually found it better to use static IP addresses with OpenVMS.

> I've also tried to set a static IP address but that has the startup complete but nothing works.

Which points to connectivity issues with the emulated network.

> Within simh, I have attached the XQ device to "ed0" - the ethernet device for FreeBSD. (The "show xq eth" command lists this device as #0 but also says there is no configuration information - BTW I'm running as root)
> 
> So my questions to this group are:
> 1) is there something I can do at the "simh" level to verify that the connection to the ethernet device is OK?

At the simh "console" level, I don't know.  VAX consoles are traditionally fairly simple configurations.  It would be handy if simh grew a ping or ARP command or other such, though.  (If that's not already available at the simh console, that is.)

If you have a MOP server operating on your LAN (and you probably don't), then you could toss a boot request for READ_ADDR.  On a VAX console, that looks like this:

>>> B/100 XQA0
Bootfile: READ_ADDR

If not (but if you have nmap or such on your network), you could use the same command and watch for the MOP requests on the Ethernet.


> 2) is there some way within OpenVMS that I can check that the ethernet level device is working (regardelss of the TCP/IP software)?

Presuming OpenVMS VAX V6.2 or later…

$ RUN SYS$SYSTEM:LANCP
LANCP> SHOW DEVICE /CHAR

The last line will indicate "Link Up  : Link state" if the network is working.

LANCP> SHOW DEVICE /COUNTERS 

will show you the traffic counters.

> 3) The netgear DHCP service uses 192.168.0.1 and the gateway and delivers addresses in the 192.168.0.x range up to 192.168.0.100 - what setting do I need to set up the static IP parts?

A host address outside the DHCP range.

> 
> It's been a long time since I've played in the OpenVMS space with this networking stuff, and then it was all DECnet. Therefore, I'm not sure what I should be setting as a "domain" name as I don't have a domain of my own. Do I make up something "wilma.org.au" and use that or what? (I've done this with the FreeBSD environment but I've never needed anything like that for the Mac nor any of the Windows VMs I've created).

In no particular order…

Unless you're working with network hosts associated with the Wilma Women's Heath Centre, no, don't use the wilma.org.au domain.

In general, servers are different than clients; you get different questions and there are different expectations around what you are expected to know about IP and DNS and such.

I recommend to folks that they register a "real" domain or three, and use that.  Never use a domain you don't own (eg: wilma.org.au), and never use a domain that could be or become a valid domain.  (Recent ICANN decisions make it far harder to create a domain that could not eventually turn into a real domain, too.)   If you have the budget, register both example.com and example.net, and use one for external hosts and one for internal addresses; for stuff known to or accessible from outside and for stuff inside your network firewall and perimeter.

If you don't have a domain, then you can look to use whateverhost.site or whateverhost.internal (there's not AFAIK agreement here; these TLDs aren't official usage, but a number of folks do use these two TLDs) within your local DNS.

As for your other client boxes, yes, you probably did get asked for a domain.  Your DHCP client boxes probably asked for that domain setting from your DHCP server, back when that was configured. As mentioned, OpenVMS doesn't know how to do that (DHCP) all that well here, nor does OpenVMS know how to use something akin to Zeroconf/mDNS or such to configure itself.