Problems with LAN

I'm having some problems getting two computers on a would-be LAN to see
each other.

Newbie warning: I'm very new at networking, so please be verbose with any
advice.

I have two computers.

Computer #1 is running Mandrake 10.1 and has three NICs:
eth0 is broken.
eth1 is being used for ADSL.
eth2 is the one I want to use for my LAN. The NIC works. I successfully
pinged it and went on-line with ADSL through it.

Computer #2 is running Windows XP home and has one NIC. The NIC works.

The cable is a recently purchased crossover cable and I have made sure it
is firmly in place. I disabled the firewalls for the two machines while
trying to establish the connection. There are no hubs, switches, or
anything like that between the two machines.

Btw, the NIC for eth0 is on the motherboard, broken, not in use, and has
never interfered, so I've just left it alone. When it broke, I stuffed in
a new NIC, Mandrake configured it as eth1, and it seemed to work just
fine, so I figured I'd let sleeping dogs lie and just not use eth0. Bad
idea? Could it be an issue?

Nothing produces an error message except for two commands:

mii-tool eth2
eth2: no link

and:

ifup eth2
dmesg | grep eth2
eth2: link down
eth2: no IPv6 routers present
eth2: link down

What does "no link" mean? It sounds like it might be something with the
cable. How likely does it seem that it would be the cable? How many cables
are defective from the getgo? As I said, it was newly purchased.

It's usually the small things, so am I using ping right?

ping -c 4 -I eth2 192.168.0.2

(192.168.0.2 is the IP I've configured for computer #2)

The ping gives me "Destination Host Unreachable". Pinging from computer #2
to 192.168.0.1 (computer #1's IP) gives me a ping timeout, but that's
maybe just a difference between windows ping and linux ping.

Also, what is my /etc/sysconfig/network-scripts/ifcfg-eth2 supposed to
look like, in this case? The guide I read for it didn't address what I'm
trying to do.

I have

DEVICE=eth2
BOOTPROTO=none
ONBOOT=yes
BROADCAST=192.168.0.255
IPADDR=192.168.0.1
NETWORK=192.168.0.0
NETMASK=255.255.255.0
FORWARD_IPV4=false

Henrik wrote:

> I'm having some problems getting two computers on a would-be LAN to see
> each other.
>
> Newbie warning: I'm very new at networking, so please be verbose with any
> advice.
>
> I have two computers.
>
> Computer #1 is running Mandrake 10.1 and has three NICs:
> eth0 is broken.
> eth1 is being used for ADSL.
> eth2 is the one I want to use for my LAN. The NIC works. I successfully
> pinged it and went on-line with ADSL through it.
>
> Computer #2 is running Windows XP home and has one NIC. The NIC works.
>
> The cable is a recently purchased crossover cable and I have made sure it
> is firmly in place. I disabled the firewalls for the two machines while
> trying to establish the connection. There are no hubs, switches, or
> anything like that between the two machines.
>
> Btw, the NIC for eth0 is on the motherboard, broken, not in use, and has
> never interfered, so I've just left it alone. When it broke, I stuffed in
> a new NIC, Mandrake configured it as eth1, and it seemed to work just
> fine, so I figured I'd let sleeping dogs lie and just not use eth0. Bad
> idea? Could it be an issue?
>
> Nothing produces an error message except for two commands:
>
> mii-tool eth2
> eth2: no link
>
> and:
>
> ifup eth2
> dmesg | grep eth2
> eth2: link down
> eth2: no IPv6 routers present
> eth2: link down
>
> What does "no link" mean? It sounds like it might be something with the
> cable. How likely does it seem that it would be the cable? How many cables
> are defective from the getgo? As I said, it was newly purchased.
>
> It's usually the small things, so am I using ping right?
>
> ping -c 4 -I eth2 192.168.0.2
>
> (192.168.0.2 is the IP I've configured for computer #2)
>
> The ping gives me "Destination Host Unreachable". Pinging from computer #2
> to 192.168.0.1 (computer #1's IP) gives me a ping timeout, but that's
> maybe just a difference between windows ping and linux ping.
>
> Also, what is my /etc/sysconfig/network-scripts/ifcfg-eth2 supposed to
> look like, in this case? The guide I read for it didn't address what I'm
> trying to do.
>
> I have
>
> DEVICE=eth2
> BOOTPROTO=none
> ONBOOT=yes
> BROADCAST=192.168.0.255
> IPADDR=192.168.0.1
> NETWORK=192.168.0.0
> NETMASK=255.255.255.0
> FORWARD_IPV4=false
>
Not all NICs are happy with crossover connections. Get a couple of
regular cables and a switch.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.

Are you sure it's a crossover cable? If you have a crimper, you can
make your own. Check the pinouts.

With the little tang pointed away from you and the cable hanging down,
look at the back side (non-tang side). Pin 1 is on your left in this
orientation and pin 8 is on your right.

A crossover cable should have:

pin 1 to pin 3
pin 2 to pin 6
pin 3 to pin 1
pin 6 to pin 2

The rest don't matter for 100 mbit

CJT wrote:

> Not all NICs are happy with crossover connections. Get a couple of
> regular cables and a switch.

What is the difference between using a crossover cable and connecting to a
switch? There's certainly no signal difference.

"CJT" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)

> Not all NICs are happy with crossover connections. Get a couple of
> regular cables and a switch.

Huh? NICs don't have emotions; they don't know the difference.

James Knott wrote:

> CJT wrote:
>
>
>>Not all NICs are happy with crossover connections. Get a couple of
>>regular cables and a switch.
>
>
> What is the difference between using a crossover cable and connecting to a
> switch? There's certainly no signal difference.
>
I don't know, but I have read multiple reports from sources I trust that
say there is. Perhaps it's an interaction between two NICS both trying
to negotiate speed and duplex at the same time, or the associated
timing.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.

ynotssor wrote:

> "CJT" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)
>
>
>>Not all NICs are happy with crossover connections. Get a couple of
>>regular cables and a switch.
>
>
> Huh? NICs don't have emotions; they don't know the difference.

The speed/duplex negotiation might proceed differently. Or so I've heard.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.

CJT <(E-Mail Removed)> wrote in news:(E-Mail Removed):

> ynotssor wrote:
>
>> "CJT" <(E-Mail Removed)> wrote in message
>> news:(E-Mail Removed)
>>
>>
>>>Not all NICs are happy with crossover connections. Get a couple of
>>>regular cables and a switch.
>>
>>
>> Huh? NICs don't have emotions; they don't know the difference.
>
> The speed/duplex negotiation might proceed differently. Or so I've
> heard.
>

The autonegation can be a problem. Just hard configure the NIC in both
Windows and Linux to be same settings. Then you don't have to worry about
the auto negotation not working properly. Set to 100mb fdx assuming both
NICS will support that - otherwise use the lowest common denominator.

Klazmon.

Llanzlan Klazmon <(E-Mail Removed)> wrote in
news:Xns96CFAA4915CB8Klazmonllurdiaxorbgo@203.97.3 7.6:

> CJT <(E-Mail Removed)> wrote in news:(E-Mail Removed):
>
>> ynotssor wrote:
>>
>>> "CJT" <(E-Mail Removed)> wrote in message
>>> news:(E-Mail Removed)
>>>
>>>
>>>>Not all NICs are happy with crossover connections. Get a couple of
>>>>regular cables and a switch.
>>>
>>>
>>> Huh? NICs don't have emotions; they don't know the difference.
>>
>> The speed/duplex negotiation might proceed differently. Or so I've
>> heard.
>>
>
> The autonegation

^^^^^^^^^^^^^ that should be autonegotiation.

>

> can be a problem. Just hard configure the NIC in both
> Windows and Linux to be same settings. Then you don't have to worry about
> the auto negotation not working properly. Set to 100mb fdx assuming both
> NICS will support that - otherwise use the lowest common denominator.
>
> Klazmon.
>

CJT wrote:

>> What is the difference between using a crossover cable and connecting to
>> a
>> switch? There's certainly no signal difference.
>>
> I don't know, but I have read multiple reports from sources I trust that
> say there is. Perhaps it's an interaction between two NICS both trying
> to negotiate speed and duplex at the same time, or the associated
> timing.

I have also heard of that, but like so many "facts" that others repeat, I've
never seen it happen, nor any technical reason for it.