2 computers joined by a LAN cable

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What is the simplest software that would get them
talking to one another?

It seems that there are numerous ways to do this
but lots of petty details to work on.

Let's assume Windows OSs.


Re: 2 computers joined by a LAN cable

JD wrote:
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What do you mean by "talking" ? Exchanging files ? Supporting FTP ?
Protocols are built in "stacks", and first you have to get the physical layer
working, before anything will run on top of it.

If the interfaces are both 10/100BT, then a crossover Ethernet cable may be the
one to use. The one I have here, has a red connector on one end, and a blue
connector on the other end. That is how the manufacturer signifies the cable
type as being "crossover".

Ethernet chips supporting 1000BT (gigabit Ethernet), may also support MDI/MDIX,
a mechanism where the LAN interface crosses over the wires as part of the
negotiation procedure. Such an interface can use either kind of cable.
If I connect one or two Gigabit Ethernet equipped computers together, I can
use a LAN cable with the same color connector on both ends. That is a
"straight thru" cable. On router boxes, "straight thru" cables are used
on the LAN side, while the WAN cable may be different.

Once the link has been properly wired, my next step in the past, might have
been to assign unique private addresses to them. Like and Then, using the "ping" command, I could prove the connection
is working electrically between the two computers. Sitting on,
I could open a command prompt window and do


If you look at your Network control panel, if you'd been previously using
broadband, you might notice in the Internet Protocol (TCP/IP) Properties, the

    X   Obtain an IP address automatically

    X   Obtain DNS server address automatically

That highlights some other services that make a LAN work better.
A DHCP server, such as your router, modem/router, or some other
computer, is a means of automatically assigning IP addresses. That
saves having to do it manually. If you have no DHCP server in your
setup, then changing to manual assignment, like in my example,
is a quick way to get things working.

DNS is the service running on the network, that translates
"www.google.com" to "". The computer can only
communicate, based on numbers, so to send packets some where,
it needs an IP address to work with. If there is no DNS service
available in the setup, a desperate person could edit the "hosts"
file, and place entries in there. The default file installed in
WinXP, contains this example of how to add an entry.     rhino.acme.com

But since you're just connecting your two computers together, it's
unlikely you'd be setting up an IIS web server on one computer, and
then trying to use Firefox on the other computer. If you were doing
something like that, then setting up mappings to symbolic addresses
might help.

So that's why I get back to your definition of "talking".

There are other connectivity cases to consider. Perhaps you're
trying to do something like this, and don't know the name of the
option used on the central computer. In this diagram, the central
computer has two LAN interfaces, and runs the built-in ICS (internet
connection sharing). Its been quite a while since I used ICS, but
I think the two sides of the computer end up on their own subnets.
The central computer actually does routing, to ensure that packets
from the Second Computer, destined for the Internet, are forwarded
onto the left hand side Ethernet interface. DNS should work in this
case, so when you type in "rhino.acme.com" in the web browser
on the second computer, the broadband_modem and DNS server at the
ISP, may do the DNS translation and return the number for it.
I've only used this setup, while doing benchmark testing on
two gigabit interfaces on the two connected computers, while
at the same time, being able to web surf from the second computer.

    broadband_modem ---------- Windows ICS ------------- Second Computer


Now, that is perhaps a more useful "talking" configuration,
if the person on the right expects their web browser to work
for example. You could, for example, do dialup networking on the
left hand side, and share one dialup session with two computers

This kind of configuration is a bit more boring. You might run
FTP, or set up a web server and web browser, or maybe a printer,
but other than that, there might not be a lot of other fun things
to do. I suppose you could always set up a game server in your
basement, and put extra LAN interfaces on the computer, to make
a very expensive router. This doesn't need ICS, and you can choose
your own IP addresses if there are no other sneak paths to the real
Internet. 192.168.x.x addresses are private, so should not be transmitted
by your network equipment (like, outside your house). They'll
be translated by some NAT device, before appearing as remapped
packets using your "public" address assigned by the ISP to your
broadband router or dialup modem.

                          First Computer ------------- Second Computer

By manually assigning addresses, network mask, and providing a bogus
gateway address, you can probably get ping running. But it'll take
a bit more creative thought and planning, to do applications on top of

Any site that specializes in home networking, should be able to walk
you through how to set up the Network control panel.


Re: 2 computers joined by a LAN cable

Paul wrote:
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I can never thank you enough Paul. Will be back to
your post later today.

Re: 2 computers joined by a LAN cable

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A short version of Paul's answer - if you are connecting the PCs together
*directly* (not via a network), then a normal LAN cable (sometimes called
patch) won't work - you need a 'crossover cable'.

Re: 2 computers joined by a LAN cable

On 6/23/2010 3:48 AM, GT wrote:
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Just an extra 2 cents here:

I would recommend using a regular cable + crossover adapter instead of a
crossover cable.  For one off situations I guess it doesn't matter much,
but I find that the adapters simplify options in the long run.

http://www.thinkgeek.com/gadgets/tools/7470 /


Re: 2 computers joined by a LAN cable

Grinder wrote:
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Thank you Grinder for the suggestion.

Now you, and earlier Paul about IDE to ATA, have
jogged my memory about these adapters. I will do a
few searches and, if nothing turns up, I contact a
small local computer store - the only one in the

Thanks again to all  :-)

Re: 2 computers joined by a LAN cable

GT wrote:
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Thank you GT. You have brought back memories.
About 20 years ago I actually
modified a parallel cable to a crossover. As I
recall there was only one wire to
be adjusted. I am the kind of guy who loathes
throwing away things he has made,
so I will go through my boxes to check if I still
have it or gave it away to someone.

Back soon :-)

Re: 2 computers joined by a LAN cable

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Same with a network cable - there are only about 7 wires in there, so you
just need to swap a few round, but you really need a crimping tool to put
the connector back on.

Re: 2 computers joined by a LAN cable

GT wrote:
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Thanks again GT.

I found a USB cable with the usual rectangular
plug on each end. In the middle
is a lump with USB Network Cable written on it. I
assume some crossover happens there.
I have this cable connected to the computer and
Netbook and I am having the same zero success as I
had when both boxes were on the network and both
could see the Internet.
Either that USB cable is defective or the software
is killing me.

Re: 2 computers joined by a LAN cable

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You have to give your network a name

Re: 2 computers joined by a LAN cable

JD wrote:
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That's a "ping pong" cable.

Normally, USB cannot be connected between two (peer) computers. It
was intended for host to peripheral connections.

The "blob" in the center of the cable, contains a chip. The chip has
FIFO buffers in it, in each direction. One computer uses it like a
"mail drop", and puts a packet in the buffer. The other computer
thinks the packet is coming from some peripheral, and transfers
the packet when it sees one in the buffer.

To use such a thing, needs software. I understand there are two driver
package types provided with those products. One is a "network stack". The
other is enough connectivity, to operate "file transfer utilities" on
either side of the cable.

The "network stack" case, should provide roughly the same facilities as
using two Ethernet chips and a TCP/IP stack. If you had that driver installed,
you should be able to use the network control panel, assign addresses or
whatever. I read somewhere, that the network stack had been built-in to
some version of Windows, but I don't know what it's called, what files
it uses. So either it works automatically, or if you have an older
OS, you'd have to install something.

Once you have some TCP/IP infrastructure in place, a home networking
web site page, should help you from there.

If the cable you bought, only seems to support the "file transfer utility"
case, then it may not be quite as easy to get TCP/IP networking going on it.
It all depends on whether the chip in the blob in the middle of the cable,
meets whatever standard they set for it. For Microsoft to include their
own driver, implies the USB committee must have defined a standard for it.


Example of a chip supporting Microsoft RNDIS. This would be the chip
inside the blob, in the center of the cable.


A project mentioning RNDIS in passing.



Re: 2 computers joined by a LAN cable

Paul wrote:
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I'll have to search some more for that early
crossover cable.

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Thanks again Paul. You are a huge mine of
information. I have been working
all day and am close to exhaustion.

I brought my two boxes together with the lumpy
cable. As you anticipated,
there was no trace of any connection. However, I
did have some interesting
moments. I managed to copy my Win2K backup disk
from my main box to my
external drive and I connected that drive to the
NetBook. I had hoped that I
could copy the backup from there to the D: drive
of the NetBook and then
install Win2K. I did get it copied ok but when I
tried to install - not a chance.
Here was the message I was shown:

"This CD-Rom is from an older version of Windows
than the one you are
presently using. Setup functionality from this
disk will be disabled."

Wow, doesn't MS think that it can control
everything? I am close to the point of
wiping Win 7 off the NetBook and, while laughing,
I'll replace it with Win2K.

Will try to answer your considerable efforts

Have a great night tonight and a great day
tomorrow  :-)

Re: 2 computers joined by a LAN cable

JD wrote:

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Windows Oses have support for multibooting on a single physical disk.
The idea is, you install the more modern OS, *after* the older OS is installed.
Doing so, allows the installer on the more modern OS, to make
entries in its Boot Manager for the older OS.

If you reverse the order, install Win7 first, then try to install
Win2K, then Win2K has no idea what Win7 is. Win7 uses a different
boot management method and files, than Win2K or WinXP. There may be
chaos if you move forward with that. To back out, you might have to
run whatever repair facilities Win7 has.

So there may be some method to Microsoft's madness. They may
be looking out for you, and trying to prevent your Win7 install
from being trashed.

In some cases, when I want to understand the issues, I use a Virtual PC 2007
session, and one or more virtual disks, to investigate. The only issue with
Windows OSes, is activation, and unplugging the network cable, might be
enough for me to do a few experiments. If you want to understand what
*could* happen, that provides a relatively tidy way of experimenting.
It's certainly cut down on the number of times I've had to physically
disconnect disks here to experiment.

Your netbook may not have enough room for multiple disks. If you place
one OS on each physical disk, that avoids boot manager issues. You steer
which OS boots, using the BIOS popup boot menu (F8 or F10) or by using
the BIOS hard drive boot order. I use two separate disks here, for my
two regular OSes (WinXP and Win2K). I press F8 in my BIOS, to be able
to select which drive to boot. Doing it that way, means neither of my
boot managers is compromised, with a pile of alternate OSes to boot.

I don't regularly use both OSes. One OS is the "maintenance OS" for the
other. Booting Win2K, I can do things to the WinXP OS files if I need to.

While I've dealt with boot managers and setting them up, I don't really
want to run my computer like that on a regular basis. In general,
regardless of which OS installer disk I'm using, I find them uniformly
bad, and they always assume they can trash any OS they find on the disk.
For example, a Debian installer CD, will assume the *whole* disk
belongs to it. I find such practices presumptuous. When you stick
*any* OS installer CD in a computer, it's "buyer beware". It's one
of those times, you should have your full backups completed first.


Re: 2 computers joined by a LAN cable

On Thu, 24 Jun 2010 01:43:29 -0400, Paul wrote:
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No, the Debian installer CD will only use the whole disk if you tell
it to use the whole disk.

Re: 2 computers joined by a LAN cable

Paul wrote:
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Thanks again Paul.

Your knowledge never ceases to amaze me  :-)  I am
very familiar with some of the frustrations you
have experienced, which makes me hesitant about
getting into the messy problems like the external
ATA drives on IDE computers.

To be honest, I feel attached to Win2K and, from
my experiences so far with
Win 7, I would not be unhappy if I just erased it
and replaced it with Win2K.

Can you see any great advantages to keeping the
Win 7?  Not knowing much about this stripped down
Win 7, I have no knowledge of what it can do that
I would like.
Certainly, wiping it and installing Win2K in its
place would greatly simplify things.

Re: 2 computers joined by a LAN cable

JD wrote:

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I think Win2K support stops in July or so. If you need any downloads
for it, get them *now* , as in today. The main advantage of Win7 is
it is still supported, you get security updates and so on.

If you're going to run Win2K, make sure you have a copy of SP4
downloaded and a copy of the rollup (came after the Service
Pack, but doesn't include all security updates). It's a relatively
small download, compared to a Service Pack. Having those two,
brings you mostly up to date. Windows Update will do the rest, but
not after the end of the month, when I think it'll no longer update
Win2K. There must be an exact date somewhere for Win2K, but I don't know
the day right off hand.

You'd also want to get the most recent IE6, as I had a problem with
Acrobat complaining it wouldn't install unless IE6 was patched up.
I'm not sure Win2K can take any more recent IE versions, so some SP
of IE6 may be as good as it gets. There is a trick for getting "IE6 net
install" to just dump the files in a directory, and I now use that
directory for doing an SP1 install for IE6. That's how I'll be able to
fix that when support is gone.

In terms of functionality, Win7 won't be doing things that much
different (at least, with respect to this discussion of a netbook).
Win7 supports NUMA, has processor licensing by sockets
rather than cores, and it likely a bit more secure (all that UAC :-) ).
I doubt it runs faster than Win2K. Win2K would run in less memory.
Win2K has poor support for 3D games now, due to the hard coding of WinXP
or later checks into the games, so if you wanted to run a 3D game on
Win2K, it takes some hacking of the game code. So support was already
lagging for that, a couple years ago. If you just want to do email
or the like, or run some third party software like an old copy of Photoshop,
that wouldn't be a problem. Win7 will have better support for SSDs,
for things like TRIM, or for 4K sector disks if you use them. If your
netbook uses an SSD (solid state disk), then Win7 might be a better choice.
You can still use Win2K to run the SSD, but tweaking it would require
more manual intervention. If your netbook has a regular hard drive,
then that probably isn't an issue.

Some day, you'll find a drop dead issue for Win2K, so keep an
archival copy of whatever Win7 came with the netbook.

Have fun,

Re: 2 computers joined by a LAN cable

On 6/24/2010 7:02 PM, Paul wrote:
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That may not be a hard limit.  A few months ago, I got windows update to
serve some updates for Windows 98SE.  Still, your suggestions are good

Re: 2 computers joined by a LAN cable

JD wrote:
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Get a wireless router with a built-in wired ethernet switch.
Doesn't have to be wireless, but it's about the same price,
so might as well.
Virtually every garage sale has a router for sale.
They ask up to $15, but by the end of the day, an offer of
$1 will often snag one.
 From there, it's almost automatic.  Read the router manual.
Biggest issue is your firewall.  Read the firewall manual.

Re: 2 computers joined by a LAN cable

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Most salvation army thrift stores or Savers stores will have tons of them for

Hell, if this guy was local i'd give him my old WRT54GS Linksys

Re: 2 computers joined by a LAN cable

GMAN wrote:
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Thank you JG, Mike and GMan.

I don't know much about the Debian installer and I
really have no interest in
wireless electronics. I believe our bodies are
being bombarded with too many waves of many kinds
and I doubt if that would do anything to improve
our health.  Most likely it is the opposite.

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