[ih] History question -- multi-homing

[Steve Crocker]

John,

Your message caught me by surprise.  I was involved in Tinker's initial
effort to connect to the Arpanet, but I didn't follow the full sequence.  I
am VERY interested to hear more, either on the list or offlist, whichever
you prefer.

Thanks,

Steve


On Sun, Sep 13, 2026 at 6:09 PM John Day via Internet-history <
internet-history at elists.isoc.org> wrote:

> For years in my courses and when relevant to a talk, I always tell the
> story of the cold day in February 1972. One morning Grossman came in late
> from a ARPANET PIs teleconference and told me that Tinker AFB wanted to
> join the Net and wanted redundant links. I started to say, “O great!” But
> stopped myself mid-syllable and instead said, “O, crap! that won’t work!”
> But immediately knew that the solution was to route to the host, not just
> to the interface.
>
> We left it there. We had work to do, code to write. It was so obvious
> others would see it as well. We didn’t write up an RFC on it or anything.
> But it was clear that multihoming committed a network architecture to
> routing to the node, not the interface.
>
> I guess we should have written something up.
>
> > On Sep 12, 2026, at 02:04, Tony Li <tony.li at tony.li> wrote:
> >
> >>>> Destinations are not the issue, sources are.
> >>>
> >>> Not really.  They are all addressed to the same address, the
> destination.
> >>
> >> They are because when I change interfaces on current hosts, the host’s
> source address changes. That’s breaks all sorts of things (or requires the
> gymnastics of MP-TCP, e.g.).
> >>
> >> If you recognize that having two paths to the rest of the world means a
> router, all that mess goes away.
> >>
> >> We implemented that when we double-homed hosts throughout DIv7 on both
> Ethernet and Myrinet - that’s what the 1997 paper describes.
> >
> >
> > If you recognize that hosts need addresses, then the problem also goes
> away.
> >
> > Tony
> >
>
> --
> Internet-history mailing list
> Internet-history at elists.isoc.org
> https://elists.isoc.org/mailman/listinfo/internet-history
> -
> Unsubscribe:
> https://app.smartsheet.com/b/form/9b6ef0621638436ab0a9b23cb0668b0b?The%20list%20to%20be%20unsubscribed%20from=Internet-history
>


-- 
Sent by a Verified

sender