Reviving ARPAnet

Grant Taylor cctalk at
Thu Jan 18 11:27:47 CST 2018

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?

> 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

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.

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.

> 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.

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.

Obviously addressing would be a concern.  -  I want to do some more 
digging to see if NetWare supports any form of Proxy ARP.  Hopefully 
Proxy ARP support would allow us to form proto bridges to extend the 
classful /A or /B or /C networks that the desired nodes are in.

I'm happy to ponder some more scheming and networking black magic if 
people are interested.

Grant. . . .
unix || die

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