Reviving ARPAnet

Warner Losh imp at
Wed Jan 17 16:46:35 CST 2018

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

> > On Jan 17, 2018, at 10:18, Warner Losh via cctalk <cctalk at>
> wrote:
> >
> > On Wed, Jan 17, 2018 at 5:40 AM, Noel Chiappa via cctalk <
> > cctalk at> 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.

A pre-Interop TCP/IP at that :) It's kinda why I was asking...


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