Weird network problem

[heatstor]

Hi,

My second pc running win2k3 is wired to the primary router (netgear
wireless) through a long cat 6 cable. The second pc is on a different
floor. The connection is made up of two cables joined by one simple
coupler. No problems with the setup. Recently, I replaced the coupler
with a Netgear gigbit switch, since I needed to add a third system.
Now, the second pc is not online and I get the message: network cable
is unplugged.
The cable is the same, except now going through the switch. The switch
works, as I tested it with the third pc. I changed ports of the switch
and all ports work fine. No idea what else to do. If anything, the
switch should make things better by enhancing the signal, right?
The cable length from the wireless router to the switch is about 50m
and from the switch to the second pc is another 50m.
Any help would be appreciated.

Asim.

 

[Steve Winograd [MVP]]

Hi,

My second pc running win2k3 is wired to the primary router (netgear
wireless) through a long cat 6 cable. The second pc is on a different
floor. The connection is made up of two cables joined by one simple
coupler. No problems with the setup. Recently, I replaced the coupler
with a Netgear gigbit switch, since I needed to add a third system.
Now, the second pc is not online and I get the message: network cable
is unplugged.
The cable is the same, except now going through the switch. The switch
works, as I tested it with the third pc. I changed ports of the switch
and all ports work fine. No idea what else to do. If anything, the
switch should make things better by enhancing the signal, right?
The cable length from the wireless router to the switch is about 50m
and from the switch to the second pc is another 50m.
Any help would be appreciated.

Asim.

The second PC isn't detecting its connection to the switch. It's
possible that automatic speed and duplex sensing aren't working. Try
making those settings manually on the second PC's network adapter in
Device Manager.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com

 

[Guest]

Sorry to hear about your troubles. A few things come to mind. First the (2)
cables that you are using to connect the one PC with your new switch are they
straight Cat5/6 cables. By this I mean that if you look at both ends of each
of the (2) cables are the color of the wires the exact same on each cable
from right to left on both ends or could it be that one is setup differently
because of the original use of the coupler. A standard network cable is wired
as follows:

Reading them from right to left

Brown
Brown/White
Green
Green/White
Blue
Blue/White
Orange
Orange/White

Now if you look at both ends of the cable and they are wired that way then
it is a straight cable. If by some chance you find that the Green and Orange
combination wires are reversed on one end then this is a CROSSOVER cable.
That kind of cable is used to connect (2) PC's directly without the use of a
switch or a hub or a router so you can access files or printers installed on
the PC. It can also be required to hook some routers to some hubs or switches
usually connected to the Internet port of the router to the Hub/Switch.

You don't mention the exact models of the Router or the switch! What is
listed on them in the way of descriptions of the ports? Do either of them
have a switch or diagram that states this port is to be used to daisy chain
the two units?

For clarification purposes to make sure I understand you exactly here is
what I think you have hooked up.

PC1 connected to Wireless Router
PC2 connected to Switch which is connected to Wireless Router
PC3 connected to Wireless Router

Two out of three PC's work and the one that doesn't is the only one
connected to the GIGABIT Switch. Did you try hooking up either of the other
(2) PC's that are working to the GIGABIT switch to see if it might be the
switch? Did you try the cable from the PC that isn't working on the other
PC's connected to the Wireless Router?
Are the other (2) PC's currently using wireless NIC Cards or STD NIC Card
that uses a cable?

Did you unplug the cable and check to make sure that the wires are in tight
close to the bottom of the connector without any gaps? Did you try plugging
in the cable and pressing it into the back of the PC and hold there to make
sure it wasn't loose? Did you try replacing the cable all together with
another known working cable?

Well that is all I have until I hear your response.

Joel

 

[heatstor]

Thanks for your reply. I did change the auto sense to 10Mbps Full and
that works. If I select 100Mbps (Full or half), there is a prolonged
message of acquiring IP address and finally the message that the
connecion will have limited connectivity. And there is none. With auto,
the message is simply: connection failed.
So for now I cam connected at 10Mpbs Full.
This is not a cross over cable. The exact same setup works fine when I
replace the switch with a coupler. The cable is connected to a wireless
Netgear router.
All cables are cat6. The switch I am trying to use is Netgear GS605
gigabit switch. The Nic on 2nd pc and laptop is: Broadcom NetXtreme
5751 Gigabit Controller.
I did some more testing. If I take a short cat6 cable and plug it into
the switch and connect that to my laptop, the connection is at full
1Gpbs with the auto sensing. However, if I bring the laptop to the 2nd
pc and use the long cat6 cable to connect to the laptop, it displays
the same behavior. Does this mean something is wrong with the second
long cable? Maybe its loosing its strength and only allows 10Mbps.
Also, I crimped the RJ-45 on this cable myself. Could it be some
problem there. What baffles me is why with the coupler instead of
gigabit switch, all works at full speed.
If this post is confusing, let me reiterate the main points, using a
laptop to test:
All cables originate from a Netgear wireless router which works fine.
One long cable, with a coupler(the $2 type) in between (so basically
there are 2 long cat 6 cables) works fine when connected to a laptop.
When coupler is replaced by switch, the long cable only connects at 10M
for the laptop.

From the same switch, if another cable (short) cat 6 cable is used to

connect to the laptop, it works fine with auto sense and connects at
1Gps.
Thanks for any advice.

Asim.

 

[Kerry Brown]

Hi,

My second pc running win2k3 is wired to the primary router (netgear
wireless) through a long cat 6 cable. The second pc is on a different
floor. The connection is made up of two cables joined by one simple
coupler. No problems with the setup. Recently, I replaced the coupler
with a Netgear gigbit switch, since I needed to add a third system.
Now, the second pc is not online and I get the message: network cable
is unplugged.
The cable is the same, except now going through the switch. The switch
works, as I tested it with the third pc. I changed ports of the switch
and all ports work fine. No idea what else to do. If anything, the
switch should make things better by enhancing the signal, right?
The cable length from the wireless router to the switch is about 50m
and from the switch to the second pc is another 50m.
Any help would be appreciated.

Asim.

Reading through the thread and your troubleshooting I agree with Joel
Kaplan. It sounds like a bad cable. His colour codes don't sound right
though. Here's a link to what the cables should look like.

http://www.bluemax.net/techtips/networking/Wiring_Tips/Wiring100TX/colorcodestandards.htm

Try replacing both ends on the cable one at a time testing after each one.
Makes ure the cable is unplugged at both ends when working on the cable. If
that doesn't work you'll have to follow the cable run and look for kinks,
staples through the cable, etc.

 

[Guest]

Hi Kerry,

Thanks for agreeing with me. If you will look at your link you added. Go to
the very bottom diagram on the left you will see that is the straght cable I
mentioned. As for the crossover cable I didn't specify exactly what the
colors were. I only mentioned that orange and green would be switched on one
end.

Joel

 

[Kerry Brown]

The correct colors right to left for a T568A standard cable should be:

brown
brown/white
orange
blue/white
blue
orange/white
green
green/white

The colors don't actually matter. All that matters is that pin one and two
use one pair and three and six another pair. I have seen many premade cables
that don't use a standard color coding. Many use the T568B standard. As long
as the right pins are used the colors don't matter. In the above example the
only pairs used are green, green/white and orange, orange/white. In your
example pins three and six are not using the same pair.