4 Jan
2019
4 Jan
'19
8:34 a.m.
(I originally posted this to hacker news, but I’ll repost it here too.)
At the University of Maryland, our network access was through the NSA's
"secret" MILNET IMP 57 at Fort Mead. It was pretty obvious that UMD got their
network access via NSA, because mimsy.umd.edu had a similar "*.57" IP address as
dockmaster, tycho and coins.
https://emaillab.jp/dns/hosts/
HOST : 26.0.0.57 : TYCHO : PDP-11/70 : UNIX : TCP/TELNET,TCP/SMTP,TCP/FTP :
HOST : 26.0.0.57 : DOCKMASTER.NCSC.MIL,DOCKMASTER.DCA.MIL, DOCKMASTER.ARPA :
HONEYWELL-DPS-8/70 : MULTICS : TCP/TELNET,TCP/FTP,TCP/SMTP,TCP/ECHO,TCP/DISCARD,ICMP :
HOST : 26.1.0.57 : COINS-GATEWAY,COINS : PLURIBUS : PLI ::
HOST : 26.2.0.57, 128.8.0.8 : MARYLAND,MIMSY,UMD-CSD,UMD8,UMCP-CS : VAX-11/780 : UNIX
: TCP/TELNET,TCP/FTP,TCP/SMTP,UDP,TCP/ECHO,TCP/FINGER,ICMP :
https://multicians.org/site-dockmaster.html
Whenever the network went down (which was often), we had to call up a machine room at Fort
Mead and ask them to please press the reset button on the box labeled "IMP 57".
Sometimes the helpful person who answered the phone had no idea which box I meant, so I
had describe to him which box to reset over the phone. ("Nope, that didn't work.
Try the other one!" ;) They were even generous enough to issue us (CS department
systems staff and undergrad students) our own MILNET TACACS card.
On mimsy, you could get a list of NSA employees by typing "grep contact
/etc/passwd", because each of their courtesy accounts had "network contact"
in the gecos field.
Before they rolled out TACACS cards, anyone could dial up an IMP and log in without a
password, and connect to any host they wanted to, without even having to murder anyone
like on TV:
https://www.youtube.com/watch?v=hVth6T3gMa0
I found this handy how-to tutorial guide for "Talking to the Milnet NOC" and
resetting the LH/DH, which was useful for guiding the NSA employee on the other end of the
phone through fixing their end of the problem. What it doesn't mention is that the
key box with the chase key was extremely easy to pick with a paperclip.
Who would answer the Milnet NOC's 24-hour phone was hit or miss: Some were more
helpful and knowledgeable than others, others were quite uptight.
Once I told the guy who answered, "Hi, this is the University of Maryland. Our
connection to the NSA IMP seems to be down." He barked back: "You can't say
that on the telephone! Are you calling on a blue phone?" (I can't remember the
exact color, except that it wasn't red: that I would have remembered). I said,
"You can't say NSA??! This is a green phone, but there's a black phone in
the other room that I could call you back on, but then I couldn't see the
hardware." And he said "No, I mean a voice secure line!" I replied,
"You do know that this is a university, don't you? We only have black and green
phones.”
Date: Thu, 11 Sep 86 13:53:45 EDT
From: Steve D. Miller <steve(a)brillig.umd.edu>
To: staff(a)mimsy.umd.edu
Subject: Talking to the Milnet NOC
This message is intended to be a brief tutorial/compendium of
information you probably want to know if you need to see about
getting the LH/DH thingy (and us) talking to the world.
First, you need the following numbers:
(1) Our IMP number (57),
(2) Mimsy's milnet host address (26.2.0.57),
(3) The circuit number for our link to the NSA
(DSEP07500-057)
(4) The NOC number itself (692-5726).
Second, you need to know something about the hardware. There
are three pieces of hardware that make up our side of the link:
the LH/DH itself, the ECU, and the modem. The LH/DH and the
ECU are the things in the vax lab by brillig; the ECU is the
thing on top (with the switches), and the LH/DH is the thing
on the bottom. The normal state is to have the four red LEDs
on the ECU on and the Host Master Ready, HRY, Imp Master Ready,
and IRY lights on at the LH/DH. If these lights are not on,
something is wrong. If mimsy is down, then we'll only have some
of the lights on, but that should fix itself when mimsy comes up.
Some interesting buttons or switches on the ECU are:
reset - resets something or another
stop - stops something or another
start - restarts something or another
local loopback -- two switches and two leds; you may need
to throw one or the other of these if the NOC asks
you to. These loopback switches should be distinguished
from those on the modem itself.
remote loopback -- like local loopback, but does something else.
The modem is in the phone room beside the terminal room (rm.
4322, if memory serves). It can be opened with the chase key from
the key box...but if someone official and outside of staff asks
you that, you probably shouldn't admit to it. It has a switch on
it, too; it seems that switch normally rests in the middle, and
there's a "LL" setting to the left which I assume puts the modem in
local loopback mode.
Now that you have some idea of where things are, call the NOC.
Identify yourself as from the University of Maryland, and say that
we're not talking to the outside world. They will probably ask for
our Milnet address or the number of the IMP we're connected to,
and will then poke about and see what's happening. They will ask
you to do various things; ask if you're not sure what they mean,
but the background info above should help in puzzling it out.
Hopefully, this will make it easier to find people to fix
our net problems in the future; it's still hard to do 'cause
we have so little info (no hardware manual, for example),
but this should give us a fighting chance.
-Steve
There were rumored to be "explosive bolts" on the ARPA/MILNET gateways (whether
they were metaphorical or not, I don't know).
Here's something interesting that Milo Medin wrote about dual homed sites like NSA
and NASA, that were on both the ARPANET and MILNET:
To: fair(a)ucbarpa.berkeley.edu (Erik E. Fair)
Cc: Hackers_Guild(a)ucbvax.berkeley.edu, ucdavis!ccohesh(a)ucbvax.berkeley.edu
Subject: Re: a question of definition
Date: Thu, 29 Jan 87 15:33:35 PST
From: Milo S. Medin (NASA ARC Code ED) <medin(a)orion.arpa>
Right, the core has many gateways on it now, maybe 20-30. All the LSI's will
be stubbed off the core however, and only buttergates will be left after
the mailbridges and EGP peers are all converted. Actually, I think DARPA is
paying for it all...
Ames is *not* getting a mailbridge. You are right of course, that we could
use 2 gateways, not just 1 (actually, there will be a prime and backup anyways),
and then push routing info appropriately. But that's anything but simple.
Firstly, the hosts have to know which gateway to send a packet to a given
network, and thus have to pick between the 2. That's a bad idea.
It also means that I have to pass all EGP learned info around on the
local cable, and if I do that, then I can't have routing info from
the local cable pass out via EGP. At least not without violating
the current EGP spec. Think about it. It'd be really simple to
create a loop that way. Thus, in order to maximize the use of both
PSN's, you really need one gateway wired to both PSN's, and just
have it advertise a default route inside. Or use a reasonble IGP,
of which RIP (aka /etc/routed stuff) is not. I'm hoping to get
an RFC out of BBN at this IETF meeting which may go a long way in
reducing the use of RIP as an IGP.
BTW, NSA is an example of a site on both MILNET and ARPANET but without
a mailbridge...
There is no restriction that a network can only be on ARPANET or MILNET.
That goes against the Internet model of doing things. Our local
NASA gatewayed nets will be advertised on both sides. The restriction
on BARRNet is that the constituent elements of BARRNet do not all
have access to MILNET. NSF has an understanding with DARPA and
DCA that NSFnet'd sites can use ARPANET. That does not extend to
the MILNET. Thus, Davis can use UCB's or Stanford's, our even NASA's
ARPANET gateways, with the approval of the site of course, but
not MILNET, even though NASA has MILNET coverage. Thus we are required
to restrict BARRNet routing through our MILNET PSN. If we were willing
to sponsor UCB's MILNET access, for some requirement which NASA
had to implement, then we would turn that on. But BARRNet itself will
but cutoff to MILNET (and probably ARPANET too) at Ames, but not
cut off to other NASA centers or sites that NASA connects. There is
no technical reason that prevents this, in fact, we have to take
special measures to prevent it. But those are the rules. Anyways,
mailbridge performance should improve after the conversion, so
UCB should be in better shape. And you'll certainly be able to
talk to us via BARRNnet... I have noticed recently that MILNET<->
ARPANET performance has been particularly poor... Sigh.
The DCA folks feel that in case of an emergency they may be
forced to use an unsecure network to pass certain info around. The
DDN brochure mentions SIOP related data for example. Who knows,
if the balloon goes up, the launch order might pass through Evans
Hall on its way out to SAC... :-)
Milo
I dug up an "explosive bolts" reference -- fortunately that brilliant plan
didn't get far.
(Milo Medin knows this stuff first hand:
https://innovation.defense.gov/Media/Biographies/Bio-Display/Article/139585…
)
To: fair(a)ucbarpa.berkeley.edu (Erik E. Fair)
Cc: ucdavis!ccohesh(a)ucbvax.berkeley.edu, Hackers_Guild(a)ucbvax.berkeley.edu
Subject: Re: a question of definition
Date: Thu, 29 Jan 87 12:29:36 PST
From: Milo S. Medin (NASA ARC Code ED) <medin(a)orion.arpa>
Actually its:
SCINET -- Secret Compartmented Information Net (if you don't know what
compartmented means, you don't need to ask)
DODIIS -- DoD Intelligence Information Net
The other stuff I think is right, at least without me looking things
up. I probably shouldn't have brought this subject of the secure part
of the DDN up. People like being low key about such things...
Erik, all the BBN gateways on MILNET and ARPANET currently comprise
the core, not just mailbridges. Some are used as site gateways, others
as EGP neighbors, etc... And just because you are dual homed doesn't mean
you get a mailbridge. And the IETF doesn't deal with low level stuff
like that; DCA does all that. In fact, the reason we are getting an
ARPANET PSN is because when DCA came out to do a site survey, they
liked our site so much they asked if they could put one here! It's
amazing how many sites have tried to get ARPANET PSN's the right
way and have had to wait much longer than us... BTW, since we are
dual homed (probably a gateway with 2 1822 interfaces in it), we
are taking steps to be sure that people on ARPANET or MILNET can't
use our gateway to bypass the mailbridges. The code will be hacked
to drop all packets that aren't going to a locally reachable network.
BARRNet, even though its locally reachable, will be excluded
from this however, since the current procedural limitations call for
not allowing any BARRNet traffic to flow out of BARRNet to MILNET
and the reverse. NASA traffic of course can traffic through BARRNet,
and even use ARPANET that way (though that's not a big deal when
we get our own ARPANET PSN). That's because only NASA is authorized
to directly connect to MILNET, not UCB or Stanford, etc...
DCA must have the ability to partition the ARPANET and MILNET in
case of an "emergency", and having non-DCA controlled paths between
the nets prevents that. There was talk some time ago about putting
explosive bolts in the mailbridges that would be triggered by
destruct packets... That idea didn't get far though...
The DDN only includes MILNET,ARPANET,SCINET,etc... Not the attached
networks. If it did, you'd need to file a TSR to add a PC to your
local cable. A TSR is a monstrous piece of paperwork that needs to
be done anytime anything is changed on the DDN... Rick knows all
about them don't you Rick?
The whole network game is filled with acronyms! I gave up trying
to write documents with full explainations in terms long ago...
I have yet to see a short and concise (and correct) way of describing
DDN X.25 Standard Service for example... That's probably one of the
harder things about getting into networking these days. We won't
even talk about Etherbunnies and Martians and other Millspeak...
Milo '1822' Medin