HDTenEightyP/NetNews huggingface dataset:
From: dos@major.panix.com (Dave O'Shea)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: spanning tree bridge specifications
Date: Mon, 28 Sep 92 19:24:59 EDT
Organization: ACME products - artillery division

seifert@netcom.com (Rich Seifert) writes:

> In article <1992Sep23.215355.16355@klaava.Helsinki.FI>, vhalkka@klaava.Helsin
> > 
> > I would consider buying normal bridges with normal
> > spanning tree. And disabling it where it is not necessary.
> > 
> I strongly disagree with disabling Spanning Tree. There is a good reason 
> for the protocol; it eliminates total network failure caused by a single
> administrator error. I understand that there are "old" devices which
> used an incompatible protocol from the standard. However this should
> cause one to select the proper devices, not to turn off the safety net.

Not to play devil's advocate, but.. What if a particular bridge is not a
necessary part of a spanning tree? ie. a bridge connected to an
end-point on the network? Or one for which no alternate path exists? The
example of a single bridge passing information across a long-distance T1
might not have an alternate path, nor would any of the bridges on the
other side of it. Would it not be better to have this bridge ignore - or
not even pass - reconfiguration messages?


--
"A leopard never changes his stripes" 
           -- Al Gore, candidate for vice-president
From: vhalkka@klaava.Helsinki.FI (Vesa Halkka)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Surge protection for ThinWire
Date: 6 Oct 92 13:32:43 GMT
Organization: University of Helsinki

The Spec says that ethernet connections are floating and the insulation
should take 500V-2kV before breaking. Most ethernet cards I have seen
have a glim lamp or some other discharge tube to protect the circuitry
from large voltages. But a lightning can burn anything..

Normal AC from the wall plug should not burn any gear (except the AC fuse,
if the ethernet is properly grounded..) also a terminator can burn
if the voltage is applied to the center conductor.

We use only fiber between buildings.. connecting the grounds of 2
buildings is always risky and generates currents to the wire.

We have measured 80 V AC to the ground on a working but flaky
ethernet segment..

--
Vesa Halkka                       -O___/ 
University of Helsinki CC:         (  /   	 vhalkka@helsinki.fi 
Centre for scientific computing:  ~~~~~  	 vhalkka@csc.fi
Newsgroups: comp.dcom.lans.ethernet
From: barr@tramp.Colorado.EDU (BARR DOUG)
Subject: Wave shape and frequency of 10Base2
Organization: University of Colorado, Boulder
Date: Mon, 5 Oct 1992 17:27:04 GMT

I have been curious for some time now to look at an ethernet signal
with an oscilloscope. I finally found time to do it and it is very
interesting what I see. I put the probe on an open end of a 10base2
(thinwire) connector. The scope is able to synch on 4 wave shapes
These wave shapes are a 10Mhz sine wave, a second 10Mhz sine wave,
180 degrees out of phase. The other two waves are a 5Mhz wave and
a second 5Mhz wave 180 degrees out of phase (these waves appear to
have a sinusoidal rise and fall time with a straight line connecting the
rise and fall). The four waves represent a 0 followed by a 0, a 1 followed
by a 1, a 0 followed by a 1 and a 1 followed by a 0 (correct me if I am
wrong). The amplitude of all the waves is from 0 volts to -2 volts.



Newsgroups: comp.dcom.lans.ethernet
From: "blair groves" <blair.groves@canrem.com>
Subject: 10bt to thin convertor
Reply-To: "blair groves" <blair.groves@canrem.com>
Organization: Canada Remote Systems
Distribution: comp
Date: 1 Oct 92 16:17:23 EST

to: oberman@ptavv.llnl.gov

The thin to 10 Base T convertor you describe from Cabletron and
Synoptics isn't quite a repeater, rather it is made from two tranceivers
back-to-back, with the AUI  interface cross-wired much like a RS232 null
modem. It doesnt repeat the signal, and shouldn't be considered as a
repeater though.

blair.groves@canrem.com
---
--
Canada Remote Systems  - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044
From: jrd@cc.usu.edu
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: NI5010 ethernet board
Date: 6 Oct 92 16:46:47 MDT
Organization: Utah State University

In article <1992Oct6.204928.16487@wam.umd.edu>, fcawth@wam.umd.edu (Alfred B. Cawthorne) writes:
> Does anybody have any information about this card?  I have 2 of them which
> I would like to write 386bsd drivers for, and I have the source for the 
> packet drivers.  Unfortunately, I do not have any manuals, etc... and I need
> to know the jumper settings for some nice addresses, interrupts, etc...
> Any email would be greatly appreiated.
> 
> Fred.
----------
	I don't want to appear discouraging, but the NI5010 board is of the
same first generation as the 3C501 board. That means it will have severe
problems with even modest packet rates. Your time and effort would be better
invested in a modern Ethernet board, and one for which documentation is 
still current.
	Joe D.
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Experience with switching plugs?
From: don@rata.vuw.ac.nz (Don Stokes)
Date: Wed, 30 Sep 1992 02:09:48 GMT
Organization: Dept. of Comp. Sci., Victoria Uni. of Wellington, New Zealand.

karl@ddsw1.mcs.com (Karl Denninger) writes:
> In article <1992Sep28.105209.26767@uklirb.informatik.uni-kl.de> kirchner@uklira.informatik.uni-kl.de (Reinhard Kirchner) writes:
> >To overcome this there are now various systems of plugs on the market
> >which close the ( thin ) wire when the cable is unplugged.
> >
> >I know about such a plugging system from AMP, and some others having plugs
> >like the german telefone plugs.
> Put in good-quality UTP instead, and be done with it.

I second that.  The AMP stuff looks good, but you do get flakeys on it very
easily.  Also, the insulation-displacement connections used behind the 
faceplate _look_ good & easy to install, but in practice are pigs.  Give
me BNCs, a crimper & a good pocket knife any day for thinwire work.  10base-T
is _much_ easier to deal with for office wiring and has the distinct advantage
that one person stuffing up their link leaves everyone else alone.  

--
Don Stokes, ZL2TNM (DS555)                      don@zl2tnm.gen.nz (home)
Network Manager, Computing Services Centre          don@vuw.ac.nz (work)
Victoria University of Wellington, New Zealand.           +64-4-495-5052
From: pat@hprnd.rose.hp.com (Pat Thaler)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: another 10BASE-T <=> 10BASE2 connection question
Date: 2 Oct 92 17:25:42 GMT
Organization: HP Roseville Networks Division

You cannot connect between 10BASE-T and 10BASE2 with a balun.  The signalling
is different.  10BASE-T transmits on one pair and receives on another pair
detecting collision by simultaneous presence of transmit and receive.  10BASE2
transmits and receives from a single coax cable using current drivers and
detects collision by looking at the DC voltage resulting.  

Some companies have made baluns that allow 10BASE2 to be run over twisted
pair, but you have to have a balun and a 10BASE2 transceiver on each end.
I am making no statement about whether those work or not and under what
situations, just noting that they exist.

I have also talked to a vendor of a supposed 10BASE2-to-10BASE-T balun who
had never looked at either standard and had assumed all that was needed
was to convert the impedance.  I assume that vendor corrected their ad 
because I haven't noticed it again.  

Pat Thaler
From: jonathan@gabriel.keele.ac.uk (Jonathan Knight)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Surge protection for ThinWire
Date: 5 Oct 92 21:23:02 GMT
Organization: Keele University, England

moore@raleng.mtc.com (Dave Moore) writes:

> To all you Ethernet gurus out there, does our lightning theory seem
> plausible?

We have had major lightening damage this summer.  Two strikes each took
out a lot of equipment, all of which was connected to serial terminal
lines going between buildings.  However even though the ethernet links
are thin and thick and travel many hundreds of yards along the same ducts
as the serial lines, none of the ethernet cards were affected in any
way.
From: gt@hprnd.rose.hp.com (Glenn Talbott)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Good CRC, mangled data was Re: Weird Ethernet Behavior
Date: 5 Oct 92 19:56:41 GMT
Organization: HP Roseville Networks Division

>So, what is the problem?  Well, the Unix box, of course, should probably
>not rely so much on network integrity, but more importantly, what
>network integrity has been compromised?  How can a packet get munged
>by a bad connection and still satisfy the CRC checks associated with
>Ethernet?  

It's easy to understand how a packet gets munged and still satisfies Ethernet 
CRC checks in your setup. A packet arrives through one ethernet port on
your router, it's CRC is verified and the packet is stored in router RAM.
Then the packet's MAC address is changed based on it's IP address and it is
re-transmitted out another port, with a new CRC calculated. If the packet
is munged while in router RAM, or during the transfers to or from either
ethernet port, the new CRC will still be valid, and with UDP checksumming
off you will never know.

Ask yourself: When you changed out the transceiver, did you cycle power on
the router? Reset anything on the router? I agree, it's real hard to
believe that a transceiver could munge CRC protected packets.

--

Glenn Talbott
HP PC LAN Card Diagnostic and Driver Development
Hewlett-Packard Roseville Networks Division
gt@hprnd.rose.hp.com
Newsgroups: comp.dcom.lans.ethernet
From: bair@telebit.com (Scott Bair)
Subject: Re: Ethernet address of 00: 00: 00:00:00:00
Organization: Telebit Corporation; Sunnyvale, CA, USA
Date: Sun, 4 Oct 1992 15:20:58 GMT

In article <1992Oct2.150552.18387@sci34hub.sci.com> gary@sci34hub.sci.com (Gary Heston) writes:
>In article <booth.13.0@lub001.lamar.edu> booth@lub001.lamar.edu (John Booth) writes:
>|In article <slendt.51@.unomaha.edu> slendt@.unomaha.edu (Steven Lendt - Data 
>|Comm) writes:
>|>Subject: Ethernet address of 00: 00:00:00:00:00
>
>|>Our network analyzer has found a Novell file server that says
>|>it's physical address is all zeros.  [ ... ]
>
>|An all Zeros Ethernet Address is a type of broadcast used by Sun workstations
>|and other (older) TCP/IP implmentations. The standard now is pretty much 
>|all ones (FF:FF:FF:FF:FF:FF), although most TCP/IP implementations will 
>|still give you a choice between the two. 
>
>Geez. All this time, I thought an all-zero IP address was the old broadcast
>command, instead of the Ethernet hardware address.
>
>You sure about that, John?
>
>-- 
>
>Gary Heston    SCI Systems, Inc.  gary@sci34hub.sci.com   site admin
>The Chairman of the Board and the CFO speak for SCI. I'm neither.
>"...I looked out my window, and saw Kyle Pettys' car upside down, then I


I suspect you are confusing the MAC address (48 bits long) in layer 2
of the OSI model with the IP address (32 bits long) found in layer 3.

Scott Bair
From: bradshaw@ccvax.ucd.ie
Newsgroups: comp.dcom.lans.ethernet
Subject: Jumper settings of 3c501 network card?
Date: 6 Oct 92 14:23:14 GMT
Organization: University College Dublin

Does anyone out there know the harware settings for the 3c501
ethernet card? What do each of the jumpers represent?
All replies appreciated....Thanks in advance....
My E-Mail addresses follow:-

CBRADH89@IRLEARN.UCD.IE
BRADSHAW@CCVAX.UCD.IE
Newsgroups: comp.dcom.lans.ethernet
From: J.Newman@icarus.curtin.edu.au (John Newman)
Subject: 10baseT Level V cable problem
Keywords: UTP Level V
Organization: Computing Centre, Curtin University, Perth, Western Australia
Date: Thu, 1 Oct 1992 02:24:36 GMT

I have been discussing UTP Level V cabling with one of
our cable suppliers. He has presented us with a possible
problem:
His claim is that there are currently two "versions" of level V
UTP cable:

a. Meets the "spec." to handle CDDI at 100metres but cannot
   be connected to existing RJ45s. (Due to larger cable
   diameter.)
b. Falls short of the CDDI "spec." but can be connected to
   existing RJ45s.

Is this problem real?
i.e. has anyone else heard of this?


/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
\ John Newman              J.Newman@icarus.curtin.edu.au /
/ Computing Centre,           "There is less to this     \
\ Curtin University,            than meets the eye."     /                         
/ Perth, Western Australia     - Tallulah Bankhead       \
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
From: dos@major.panix.com (Dave O'Shea)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Using different catagory wires in series
Date: Mon, 28 Sep 92 19:49:59 EDT
Organization: ACME products - artillery division

barr@tramp.Colorado.EDU (BARR DOUG) writes:

> The document also
> points out that there are connectors designed for the higher catagories, and
> implies that these connectors can be used with lower catagory wire.
> 
> I should also note that the bulliten is offered as basis for discussion and 
> is not a binding proposal and the requirements are subject to change after
> more study.
> 
> Catagory 3	for use for voice and data up to 10Mbs
> Catagory 4      for use for voice and data up to 16Mbs
> Catagory 5      for use for transmission rates up to 100Mbs

Now here's a question: Does anybody have any real-life experiences using
the "standard" unshielded, crimp-on plastic connectors at data rates up
in the 100mb/s area? I'm installing a network right now at my office,
and I'm using level 5 cable, but standard connectors. The likelyhood of
us running 100mb/s over copper is minimal, but it might be used on a few
selected stations - servers, etc. These, I could re-terminate on an
"as-needed" basis.


--
"A leopard never changes his stripes" 
           -- Al Gore, candidate for vice-president
Newsgroups: comp.dcom.lans.ethernet
From: gary@sci34hub.sci.com (Gary Heston)
Subject: Re: Wave shape and frequency of 10Base2
Reply-To: gary@sci34hub.sci.com (Gary Heston)
Organization: SCI Systems, Inc., Huntsville, Al.
Date: Tue, 6 Oct 1992 15:13:45 GMT

In article <1992Oct5.172704.29003@ucsu.Colorado.EDU> barr@tramp.Colorado.EDU (BARR DOUG) writes:
>I have been curious for some time now to look at an ethernet signal
>with an oscilloscope.  ....  I put the probe on an open end of a 10base2
>(thinwire) connector.

Interesting. Why use an open cable, instead of a properly-terminated
one?

BTW, your description doesn't resemble what I saw at all, the time 
I hooked up a Tex 465 to one of my segements (properly terminated,
of course--lots of spare T-adapters to use for that).

-- 
Gary Heston    SCI Systems, Inc.  gary@sci34hub.sci.com   site admin
The Chairman of the Board and the CFO speak for SCI. I'm neither.
"...I looked out my window, and saw Kyle Pettys' car upside down, then I
thought 'One of us is in real trouble'." Davey Allison, re: a 150MPH crash 
Newsgroups: comp.dcom.lans.ethernet
From: fillmore@emr1.emr.ca (Bob Fillmore 992-2832)
Subject: Re: Subnetting on non-byte boundaries
Organization: Energy, Mines, and Resources, Ottawa
Date: Mon, 5 Oct 1992 21:29:19 GMT

In article <1992Oct2.182031.20718@dgbt.doc.ca> phil@dgbt.doc.ca writes:
>In article 16SEP199210061324@jester.is.macsch.com, s_vossler@macsch.com (Scott Vossler) writes:
>> 
>>    We are looking at the possibility of subnetting our Class B address range,
>> using 10 bits for the network number and 6 bits for the host number.  I know
>> that the CISCO routers can handle this, but how about other vendors.  What
>> experience do the Interneter's have with non-cisco equipment and subnetting.
>> 
>>    I am interested in hearing the trials and tribulations that others have
>> encountered when subnetting on a non-byte boundary.
>> 
>>      /=====================================================================\
>>      |  Scott Vossler                  | Internet : s_vossler@macsch.com   | 
>>      |  Computer Operations & Networks | Voice    : (213) 259-4935         |
>>      |  MacNeal-Schwendler Corp        | Fax      : (213) 259-3838         |
>>      |  Los Angeles,  Calif  90041     |                                   |
>>      \=====================================================================/
>> 
>
>One problem that you have is with the nameserver if you don't stick to byte
>boundries your reverse mapping will have to be in one huge file on one machine.
>However, if you split up your B as a bunch of class C networks you can grant
>authority for the various Class C's to other nameservers.
>
>If I were running the Class B reverse mapping nameserver I would insist that the
>B is broken up into a bunch of calss C's.
>
>---
>Phil Blanchfield
>The Communications Research Centre 3701 Carling Avenue, Ottawa Ontario CANADA
>Internet: phil@dgbt.doc.ca
>

We currently use a strange mask size (20 bits - 16 subnets) and it works OK
for us.  Just make sure that you hand out IP addresses in blocks of 256
keyed on the 3rd octet of the address to different organizations.
Then in the DNS reverse translation you can use pointers keyed on the 3rd
octet pointing to the organizations' name servers; multiple pointers to one
server works OK.

-- 
Bob Fillmore, Technical Services Division          email: fillmore@emr.ca
  Information Management Branch,                   BIX:   bfillmore      
  Energy, Mines, & Resources Canada                Voice: (613) 992-2832
  580 Booth St., Ottawa, Ontario, Canada  K1A 0E4  FAX:   (613) 996-2953
From: exujlg@exu.ericsson.se (Jon L. Gauthier)
Newsgroups: comp.dcom.lans.ethernet
Subject: Re: Screen control software over Ethernet
Keywords: screen,control,ethernet
Date: 29 Sep 92 21:51:49 GMT
Organization: Ericsson Network Systems, Inc.
X-Disclaimer: This article was posted by a user at Ericsson in North America.
              The opinions expressed are strictly those of the user and
              not necessarily those of Ericsson.

In article <Pressley.6.717786829@vxc.uncwil.edu> Pressley@vxc.uncwil.edu (Mike Pressley) writes:
>From: Pressley@vxc.uncwil.edu (Mike Pressley)
>Subject: Screen control software over Ethernet
>Keywords: screen,control,ethernet
>Date: 29 Sep 92 17:13:49 GMT


>We are in the process of setting up a multi location network
>in a class room configuration. The only problem is we want
>to be able to login to any station on the net, place it in server
>mode and display its screen on every machine on the net. We
>are going to be using high resolution graphics, therefore this
>communication package must run on ethernet. Basically we
>are looking for a PC-Anywhere or Carbon Copy product that
>runs on ethernet and has one server controlling several
>nodes.

>If anyone has any idea where to purchase this product or if
>such a product exists, Please send me E-mail. Thanks very
>much.

>Mike Pressley
>Academic Computing Services
>UNC Wilmington
>pressley@vxc.uncwil.edu
>jmp@ecsvax.uncecs.edu

pcAnywhere only allows one remote to connect to a pc host.  Close-up LAN 
from Norton-Lambert allows multiple remotes (students) to connect to a 
single host pc (teacher).  You can set it up so that none or all of the 
remotes can control the host keyboard.

We would be using it locally here, but security is pretty sketchy (as noted 
above).  We use pcAnywhere v4.5 - better security (Still wish it supported 
userid/password instead of just password).

------------------------------------------------------------------------------
Jon L. Gauthier                                 Ericsson Network Systems, Inc
EXU/IS/TP Systems Programmer                                  P.O. Box 833875
+1 214 997-0157                                     Richardson, TX 75083-3875

Disclaimer:  "My opinions are my own - my employer would take the 5th on
             everything I say."  Surely it's been said before!...
------------------------------------------------------------------------------
Newsgroups: comp.dcom.lans.ethernet
From: morris@grian.cps.altadena.ca.us (Mike Morris)
Subject: Re: Can Token Ring wire be used for 10BaseT?
Organization: College Park Software, Altadena, CA
Date: Mon, 28 Sep 1992 06:23:57 GMT

pat@hprnd.rose.hp.com (Pat Thaler) writes:

>You can use IBM Type 1 or2 (150 ohm) STP to run 10BASE-T.  There is one
>significant difference between this wire and the UTP that 10BASE-T was
>designed to run on which could cause a problem.  The impedance of the
>UTP is nominally 100 ohms while the impedance of the STP is 150 ohms.
>This difference in impedance can cause reflections which interfere with
>communication.  Fortunately, the problem can be solved by using a device
>called a balun to transform the impedance and make the cable look like
>it is 100 ohms to the 10BASE-T adapter.  

>I am not saying that it will fail if you don't use a balun.  In many cases
>it works even without adapting the impedance.  The safest course is to 
>use the balun.  If no balun is used, the impedance difference is more 
>likely to cause a problem on short runs of STP than on long ones.  

The last batch of 3C503TPs I used had jumpers that included 100 and 150
ohm modes.

-- 
Mike Morris   WA6ILQ   | This space intentionally left blank.
PO Box 1130            | 
Arcadia, CA. 91077     | All opinions must be my own since nobody pays
818-447-7052 evenings  | me enough to be their mouthpiece...
Newsgroups: comp.dcom.lans.ethernet
From: bjork@telebit.com (Steven Bjork)
Subject: Good CRC, mangled data was Re: Weird Ethernet Behavior
Organization: Telebit Corporation; Sunnyvale, CA, USA
Date: Thu, 1 Oct 1992 03:20:22 GMT

In article <1ad8q7INNe3o@matt.ksu.ksu.edu>
 rrsum@matt.ksu.ksu.edu (Rick Summerhill) writes:

[detective story wrt packet mangling]

>network integrity has been compromised?  How can a packet get munged
>by a bad connection and still satisfy the CRC checks associated with
>Ethernet?  Has anyone ever seen this type of behavior before?  Does

One of the more bizzare tidbits I've seen in the Internet
Monthy Reports was how a T1 (or T3) link was swapping
a set of eight or so octets of data... Nothing like having
the order of your data changed on you on the fly!

--Steven
From: pat@hprnd.rose.hp.com (Pat Thaler)
Date: Fri, 2 Oct 1992 17:09:34 GMT
Subject: Re: Can Token Ring wire be used for 10BaseT?
Organization: HP Roseville Networks Division
Newsgroups: comp.dcom.lans.ethernet

In comp.dcom.lans.ethernet, bennett@dstos3.dsto.gov.au writes:

    In 10base5 and 10base2 there is a DC component of the 
    signal.  Does that also apply in 10baseT ?  If so, the balun wouldn't work.

In 10BASE-T, the signal has no DC component.  In 10BASE5 and 10BASE2, the
DC component is used to detect collision because it is designed to work
on a bus.  In 10BASE-T, collision is sensed by seeing a signal on the
receive pair while transmitting.  This method is also used in FOIRL for
fiber optic media. 

Pat Thaler
From: nelson@crynwr.com (Russell Nelson)
Newsgroups: comp.dcom.lans.ethernet
Subject: Packet Driver for 3C503 
Distribution: world
Date: Tue, 29 Sep 92 01:25:59 GMT
Organization: Crynwr Software

In article <1a5oogINN4ro@golem.wcc.govt.nz> macewan_h@kosmos.wcc.govt.nz writes:

   Can anyone tell me where I might find a public domain (free) Packet 
   Driver (for use with WinQVT/Net say) for a 3Com 3C503 card (not using 
   shared memory for data transfer?

FTP to simtel20.army.mil, cd to pd1:<msdos.pktdrvr>, fetch
drivers.zip which has the doccos, and then fetch drivers3.zip, which
has the version you want.

-russ <nelson@crynwr.com>  I'm proud to be a humble Quaker!
Crynwr Software            Crynwr Software sells packet driver support.
11 Grant St.               315-268-1925 Voice
Potsdam, NY 13676          315-268-9201 FAX
Newsgroups: comp.dcom.lans.ethernet