fmc at reanimators.org
Wed Jan 17 14:12:15 CST 2018
> On Jan 17, 2018, at 10:18, Warner Losh via cctalk <cctalk at classiccmp.org> wrote:
> On Wed, Jan 17, 2018 at 5:40 AM, Noel Chiappa via cctalk <
> cctalk at classiccmp.org> wrote:
>> (The latter includes NCP as well as TCP/IP.)
> I'm curious: does it inter-operate with modern TCP/IP implementations?
This is a more serious question than one might think, but I know you (Warner) have been around long enough to have gone to Interop when it was about improving network interoperability.
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.
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?
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.
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.
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