Help! Point to Point Ethernet?

Help! Point to Point Ethernet?

Post by Greg Philm » Wed, 15 Jun 1994 02:14:51



I've read the NET howto and even printed the LDP Network Admin Guide.

What I'm trying to do is connect two machines via ethernet.  Following
the advice in the NET howto, I constructed a crossover 10Base-T cable
and just plugged it into the two machines.

I get a green light on each end!  But nothing works.  Not even the DOS
network card diagnostics (works sort of like ping, I'm guessing).

I can ping my localsite on each end, but pings to each other go nowhere
(100% dropped packets).

Since the DOS program doesn't even work (under DOS, not EMU), I'm guessing
it's a cable problem.  Here's the pinouts I used:

    1 ----- 3
    2 ----- 6
    3 ----- 1
    6 ----- 2

I made this cable twice already, neither worked, but both resulted in green
"connected" lights on the network cards.

Any ideas?
--

 
 
 

Help! Point to Point Ethernet?

Post by Terry Daws » Mon, 27 Jun 1994 17:34:02



>What I'm trying to do is connect two machines via ethernet.  Following
>the advice in the NET howto, I constructed a crossover 10Base-T cable
>and just plugged it into the two machines.

Um, the NET-2-HOWTO mentions nothing about crossover cables for twisted
pair connections. The only place I can think that it mentions crossover
cables is in connecting two machines via a SLIP link. For 10base-T you need
a hub to connect machines together I think.

Terry

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Help! Point to Point Ethernet?

Post by John Wi » Tue, 28 Jun 1994 03:03:00


TR>Um, the NET-2-HOWTO mentions nothing about crossover cables for twisted
TR>pair connections. The only place I can think that it mentions crossover
TR>cables is in connecting two machines via a SLIP link. For 10base-T you need
TR>a hub to connect machines together I think.

Not really.

I asked the very same question of SMC and was told that it was possible
to direct connect 2 10BaseT cards if you create a cable with the
following pin assignments:

            PIN        PIN
            ---        ---
             1<-------->3
             2<-------->6
             3<-------->1
             6<-------->2

 
 
 

Help! Point to Point Ethernet?

Post by Denis Sola » Tue, 28 Jun 1994 00:21:45



: >What I'm trying to do is connect two machines via ethernet.  Following
: >the advice in the NET howto, I constructed a crossover 10Base-T cable
: >and just plugged it into the two machines.

: Um, the NET-2-HOWTO mentions nothing about crossover cables for twisted
: pair connections. The only place I can think that it mentions crossover
: cables is in connecting two machines via a SLIP link. For 10base-T you need
: a hub to connect machines together I think.

Well, this is not a commercial subject, but a nice thing Sys Managers
have in store...  Yes I have my Sparc and the Holly Linux Box of Slack
hooked that way, despite what the normal idea is.  I would not mind at
all giving the recipie for it, but I have to figure out the amp and
lenght parametres myself as I was given it... What a spoiler !

Now for the connection part, I must use RARP and tftp as I boot some
SunOS code off the Linux server.  Problem is the Sun must have a patch as
linux doesn't allow yet 1k NFS, else i'll be glad to hear from your
hacks, as I means I could boot the sun off the monitor commands.

I did not make that Sun thing either, there is a file called Xkernel that
combined with other scraps found at sol.ctr.columbia.edu allow it.  Few
days ago I was an ethernet illiterate.  

Now the basic principle is:
I discovered that thru rarp you can attach an IP address to an Ethernet
address of an other machine and hookem up that way.  RARP is part of the
Netkit.  Else I hope a real "good man" would come to give a better
pointer.

--


 
 
 

Help! Point to Point Ethernet?

Post by Gary Paul Gortmak » Thu, 30 Jun 1994 15:09:37



: >What I'm trying to do is connect two machines via ethernet.  Following
: >the advice in the NET howto, I constructed a crossover 10Base-T cable
: >and just plugged it into the two machines.

: Um, the NET-2-HOWTO mentions nothing about crossover cables for twisted
: pair connections. The only place I can think that it mentions crossover
: cables is in connecting two machines via a SLIP link. For 10base-T you need
: a hub to connect machines together I think.

He was probably thinking of the Ethernet-HOWTO, which includes a recipe
for sticking 2 machines together without a hub, using RJ-45/10B-T.

Paul.

 
 
 

Help! Point to Point Ethernet?

Post by William B. Catte » Mon, 11 Jul 1994 08:43:45





: : >What I'm trying to do is connect two machines via ethernet.  Following
: : >the advice in the NET howto, I constructed a crossover 10Base-T cable
: : >and just plugged it into the two machines.

: : Um, the NET-2-HOWTO mentions nothing about crossover cables for twisted
: : pair connections. The only place I can think that it mentions crossover
: : cables is in connecting two machines via a SLIP link. For 10base-T you need
: : a hub to connect machines together I think.

: He was probably thinking of the Ethernet-HOWTO, which includes a recipe
: for sticking 2 machines together without a hub, using RJ-45/10B-T.

: Paul.

The correct cable config for connecting two systems via 10BaseT is;

1       3
2       6
3       1
6       2

Wires 4,5,7 & 8 are not used in 10BaseT but should be includes to assist
in strain-relief.  The normal 10BaseT cable (when you are connecting into
a hub or concentrator) is;
1       1
2       2
3       3
6       6

Hope this helps.

Bill Cattell

 
 
 

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