Reviving ARPAnet

Frank McConnell fmc at
Thu Jan 18 16:11:01 CST 2018

> On Jan 18, 2018, at 9:27, Grant Taylor via cctalk <cctalk at> wrote:
> On 01/17/2018 01:12 PM, Frank McConnell via cctalk wrote:
>> So here's a real example: I have an HP 3000 Micro GX with MPE G.A3.09 (V-delta-9) which is very 1990.  And it has a LANIC, and V-delta-9 is late enough for it to be able to do IP over Ethernet (vs. V-delta-4 and before which could only do IEEE over 802.3).  And it has an FTP client.
> Please clarify what you mean by "IP over Ethernet", specifically what frame type?
> Are you talking about Ethernet II frames?

What I meant to write in that latter part was "IP over IEEE 802.3".  HP's LAN business started out big on big-S Standards, as in an IEEE Standard was preferred over a document circulated by three other computer companies.  That document would be Ethernet II.  So HP's initial attempts at TCP/IP were done with IEEE 802.2 framing and SAP 6, and used HP’s Probe protocol for local address discovery.  And TCP/IP was done as a stopgap, the stated plan was to support the OSI stack when it was ready.

HP did eventually (by the end of the 1980s) come to grasp that the customers really wanted Ethernet (II) so they could at least ping the 3000 to see if it was up.  Support for that (and ARP) arrived in the version of NS Transport for MPE V/E V-delta-5.

>> So you might think I'd be able to move files between it and a modern FreeBSD box, right?  I mean, it's all just Ethernet, right?
> Ethernet != Ethernet

OK, "IP over Ethernet II".  But most folks these days won’t be thinking about the other kinds.  Maybe even most folks on this list.

> I'm wondering if it might be possible to use an old NetWare 4.x / 5.x box as a router to convert from one Ethernet frame type to another Ethernet frame type.  I.e. from IP over Ethernet II frames to IP over 802.3 frames.

If you want something that was correct for the period, use a Cisco AGS router.  (I think later Cisco routers will do too.)  It can do the routing and can also proxy HP’s Probe address-resolution protocol.

The Wollongong Group had a software routing product, WIN/ROUTE, and they worked it over a bit to make another product WIN/ROUTE2 which could do the 802.3/Ethernet routing.  Can't remember whether it required 3C503 cards.

> I actually don't know if Linux can do this or not.  My typical go to tool might not help here.  :-/
>> Where it falls apart is that there's a bug in HP's TCP/IP ("NS Transport") in V-delta-9 and before, such that it tears down the connection with a failure if a packet is received with IP type-of-service not zero. And the FreeBSD FTP server sets a socket option that gets FreeBSD to send that sort of packet.
>> At a previous employer, I went round with HP a bit on behalf of a mutual customer and got HP to issue a patch for NS Transport that corrects this behavior on the MPE side.  Clearly, I don't have that patch on this system.
> I think we all have experiences like that.  Some sort of custom code that we didn't care about at the time (beyond fixing the problem) that we would now like to get our hands on years later.

Upgrading to MPE Release 40 FOS with Platform 3P SUBSYS would do; the patch did make it into later releases of NS Transport (which would be on the SUBSYS tape).

>> FreeBSD is FreeBSD, and I can build its FTP server from source and change it so it works in this situation; but I think this should give y'all some idea of the hilarity that can ensue when you exhume a 1980s TCP/IP and put it on your network.
> I wonder if there are other tricks that can be used to work around this without needing to recompile services.  I.e. use IPTables (or FreeBSD's counterpart that I don't know the name of) to change the type-of-service to something other than 0.

Been a while since I did that sort of thing but it was with ipfw, a divert socket, and a program to modify the diverted packets and hand them back down to the kernel.

Really, commenting out the setsockopt() call in ftpd seemed the easiest thing to do at the time, but I’d need to do it over now and might go for this sort of approach.

> Here's a link with a lot of gory details on NetWare's support of multiple Ethernet frame types.
> Link - Migrating Ethernet Frame Types from 802.3 Raw to IEEE 802.2
> -
> Here are the four frame types that NetWare supports:
> - Ethernet II
>    - I think this is what we are using for just about everything today.
> - IEEE 802.3 "raw"
>    - I'm speculating that this is the frame type that Frank is referring to above.
> - IEEE 802.3 with 802.2
> - IEEE 802.3 with 802.2 SNAP
> I /think/ that NetWare can bind IP to all four Ethernet frame types. Hopefully one of them is compatible with V-delta-4 and before.

If it can, I think you want the "IEEE 802.3 with 802.2" on the HP side, and the "Ethernet II" on the other side.  NS Transport did NOT do SNAP.

But back in that day, folks were mostly upgrading to later releases of MPE.  I kept this one on V-delta-9 for no real good reason (it was good enough through the 1990s) and then because I found I couldn’t read the Y2K tape set (Release 40 FOS with Platform 3P SUBSYS).

-Frank McConnell

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