[HECnet] Minimal Requirements

[Brian Hechinger]

TCP tracks the state of the connection. When I server accepts a TCP
connection it takes note of the source address and port and sends responses
there.

UDP just blindly throws packets wherever you tell it to. It does not track
state and so it has no idea where to send the response. That's why UDP
based services need to be setup on both ends.

-brian

On Sat, Apr 6, 2019, 03:44 Keith Halewood <Keith.Halewood at pitbulluk.org>
wrote:

> I know :)
>
> I think the 'other' endpoint address is only needed for UDP circuits.
>
> Keith
>
> -----Original Message-----
> From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
> Behalf Of Supratim Sanyal
> Sent: 05 April 2019 23:28
> To: hecnet at Update.UU.SE
> Subject: Re: [HECnet] Minimal Requirements
>
> You do realize that DUNE connected right back from your new IP address
> with no intervention needed at least on IMPVAX, don't you? Which would be
> encouraging news for Dave's original concern with dynamic IPs.
>
> Supratim
>
> > On Apr 5, 2019, at 2:18 PM, Keith Halewood <Keith.Halewood at pitbulluk.org>
> wrote:
> >
> > Hi,
> >
> > This is a partial repeat of another message addressed to individuals.
> >
> > Sorry I've been incommunicado. To cut a long story short, a car crashed
> into our local exchange and completely demolished it. Our internet routing
> failed over to 4G (dynamically allocated IP address ironically) so our
> source IP addresses have changed. This should not have affected email
> because we have failover there too. Due to a slight misconfiguration, this
> didn't happen properly. I've only just noticed with a whole load of
> messages bouncing back to me from our email server.
> >
> > So, as a result, at least until end of Sunday, I won't be able to accept
> incoming DECnet over TCP connections to our fixed addresses. I notice that
> area 46 is connected via 31. PIVAX0 on 29.200 is currently connectionless
> though.
> >
> > Incidentally, gmail doesn't seem to care about SPF configuration (or is
> yet to see my updated value) and so is treating mail to it from me via a
> backup route as spam and blocking it. This may fix itself shortly.
> >
> > Keith
> >
> > -----Original Message-----
> > From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On
> Behalf Of Johnny Billquist
> > Sent: 04 April 2019 23:32
> > To: hecnet at Update.UU.SE
> > Subject: Re: [HECnet] Minimal Requirements
> >
> >> On 2019-04-04 15:28, Paul Koning wrote:
> >>
> >>
> >>> On Apr 4, 2019, at 7:53 AM, Supratim Sanyal <supratim at riseup.net>
> wrote:
> >>>
> >>> On 4/4/19 6:12 AM, Keith Halewood wrote:
> >>>> Hi,
> >>>> I'm pretty sure that a TCP listen doesn't care who connects to it on
> VAX Multinet. UDP is a different matter.
> >>>> For example, there's a listener device set up with a 1.1.1.1 address
> on DUNE here. PIVAX0 connects to it from a completely different address. I
> use access controls on the router to restrict just who is allowed to
> connect to it.
> >>>> If you want I can set up another incoming line/circuit and you can
> connect to it. I'm in area 29 FYI.
> >>>
> >>> I have listeners waiting on 0.0.0.0. Yes, MULTINET does not seem to
> care what address connections come in from.
> >>
> >> Does that mean anyone can connect to HECnet without any
> authentication?  Or is DECnet node init authentication used?
> >>
> >> "Security by obscurity" only goes so far.  Is it good enough for HECnet?
> >
> > So far that's mostly what we have, yes.
> > I have from time to time considered maybe adding a password on the link,
> as DECnet do support that.
> >
> > But so far, there has never been a single instance of someone actually
> trying to connect some unknown node with DECnet on any link of mine. But it
> is most likely just because pretty much any remote script-kid just have no
> clue that DECnet even exists, what to do with it, or anything else.
> >
> > Also, the worst I think anyone could do would just be disrupting DECnet.
> > But maybe someone else can think of anything else potentially
> interesting someone could do by hijacking a circuit.
> >
> > My biggest issue with those link passwords in RSX is that I think I can
> only have one password, and it will be applied to all links. And I also
> think that maybe I had to turn it on on all links if I turn it on on any.
> >
> > But if people are willing to experiment some, we could test enabling it.
> >
> > For the bridge, though, it requires that both ends are known. No
> wildcard connections allowed.
> >
> >   Johnny
> >
> > --
> > Johnny Billquist                  || "I'm on a bus
> >                                   ||  on a psychedelic trip
> > email: bqt at softjar.se             ||  Reading murder books
> > pdp is alive!                     ||  tryin' to stay hip" - B. Idol
>
>
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