On Wed, Jan 17, 2018 at 1:12 PM, Frank McConnell via cctalk <
cctalk at classiccmp.org> wrote:
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:
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.