Hello,
I have previously posted my failure to establish a LAN, entitled, "Network cable unplugged",
between two computers with onboard Network Adapters, via a CAT 5 crossover cable. So,
I have purchased a NIC and installed it into PC2, which was the PC which always displayed,
"Network cable unplugged". However, now both computers say, "Network cable unplugged".
If I put the RJ45 plug back in the onboard network adapter socket, PC1 indicates that there is
a network connection.
Windows XP quickly found the new device, installed the appropriate driver, and told me the
device was working properly, but neither or the two LED's next to the RJ45 socket are lit.
So, what does this tell me of the problem with PC2's failure to make a network connection?
Do I have a Hardware Problem, or a Software Problem? Early on I had a look in my BIOS,
but I did not see any network adapter options or settings. I have never had the onboard network
adapter working on PC2.
Any help would be greatly appreciated.
Sincerely,
Chris B.

Dani AI

Generated

Brief follow-up and a focused troubleshooting path for that builds on 's suggestions.

Because Windows reports the NICs as "installed" while the RJ45 LEDs never come on, the problem is much more likely at Layer 1 (cable/port/hardware) than at the driver layer. Ubuntu seeing the adapters is useful information: it shows the OS can talk to the card, but it does not prove there is an electrical link or a usable IP path between the two machines.

A practical, ordered test plan:

  • Check link lights and cable first. Use a known-good cable and, if possible, a simple switch or router between the two PCs. If you must use a direct PC-to-PC cable, try a confirmed crossover cable (older NICs need one); newer NICs may auto-MDI/X but don’t rely on that. If LEDs still stay off on one end, the card or socket is suspect.
  • Use the LiveCD to isolate software from hardware. When connecting two PCs directly there is usually no DHCP server, so assign static IPs on the same subnet (for example 10.0.0.1/24 and 10.0.0.2/24) on both systems and then test connectivity. If a link LED appears when using the LiveCD + static IPs, the hardware is OK and Windows/driver/IP settings are the issue.
  • Swap parts: reseat the PCI card, try a different PCI slot, or test the card in another PC. Disable the unused on-board NIC in Device Manager (or BIOS if possible) so Windows uses only the card you are testing.
  • Interpret ping results: "Destination host unreachable" usually means no route or no link at Layer 2; "Request timed out" means packets left but no reply (firewall/IP issue). Make sure firewalls are off while testing and both machines share the same subnet and netmask.

Avoid flashing the BIOS unless you confirm a motherboard-level problem. Safer next steps are the cable/swap tests, assigning static IPs for direct links, updating chipset drivers, and testing the NIC in another machine.

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Hello, it's me again! DaniWeb doesn't appear to have any "edit" facility, and I am wanting to update my posting.

I have just put the NIC into the other PCI slot, and uninstalled the driver that my computer provided, then installed the driver that came on the floppy disk with the NIC, however, alas, nothing has changed! Why would my computer tell me that both network devices are working properly, but also tell me that they are both disconnected?

Why would my computer tell me that both network devices are working properly, but also tell me that they are both disconnected?

I think Windows XP is reffering to the cable being disconnected; it doesn't have anything to do with the card.

You may also want to try booting Windows into safe mode. Ping probably won't work, but you should check. Success would indicate a software problem.

I know this sounds crazy, but another way to check would be to download a Linux LiveCD (such as SuSE or Kubuntu), burn 2 copies, and boot both computers off these LiveCDs. If luck is on your side, Linux will recognize the network cards, and then you can see if the network connection works over Linux.

DaniWeb doesn't appear to have any "edit" facility

Yeah, any non-mod gets locked out of editing their post after 30 minutes.

Hello, Mr J Programmer,

Thank you for your suggestions.

About 'safe' mode: what should I expect that to do?

About 'Linux Live CD': what exactly is it, and how will it work? It sounds risky and complicated. Is it an operating system? I have a CD of Linux 'ubuntu', but I have not used it.

About the 'ping' thing: do you mean something like what happens in Windows XP 'Network Diagnostics'?

I read in another thread about 'Chipset Drivers', which are supposed to configure hardware and software on motherboards. Could this be a problem?

Cheers,

Chris B.

About 'safe' mode: what should I expect that to do?

There could be a process running in the background that's interfering (eg., a virus, although that's probably not the case).

About 'Linux Live CD': what exactly is it, and how will it work? It sounds risky and complicated. Is it an operating system? I have a CD of Linux 'ubuntu', but I have not used it.

A Linux LiveCD is a CD that you boot off of, and you get a whole Linux enviroment from the CD without installing anything. The Ubuntu CD will probably work.

About the 'ping' thing: do you mean something like what happens in Windows XP 'Network Diagnostics'?

Yes, the Network Diagnostics uses the ping tool (which can also be run from the DOS prompt).

Hello,

My ubuntu CD does have the Live CD facility, but It requires 256MB of RAM, and I have not yet installed an extra 128MB to the next slot.

I booted into 'safe mode', but I don't know what good that was supposed to do. When I checked out 'Network Connections', the page was blank. I suppose that makes sence, if the drivers had been deactivated by the 'safe mode'

I have run numerous 'Network Diagnostics', and they do not record any grading for the network adapters, that is they neither get a 'passed' or 'failed', nor was there a 'pinging' test done on the 'IPAddress', in fact the 'IPAddress' item was not even on the list!

Regards,

Chris B.

I have run numerous 'Network Diagnostics', and they do not record any grading for the network adapters, that is they neither get a 'passed' or 'failed', nor was there a 'pinging' test done on the 'IPAddress', in fact the 'IPAddress' item was not even on the list!

Perhaps it would be eaiser to use the command line ping tool. Open up the MS-DOS prompt, and enter the following: ping 192.168.0.1 replacing with the IP address of the other computer

On PC2, (the computer with the connectivity problem), I have 'pinged' on the 'command prompt' with the IP addresses of the new NIC, and the old onboard network adapter, both when PC2 was online, and offline. When offline, both network adapter IP address 'pings' resulted in "Destination host unreachable". When online, the results were, "Request timed out", for both of them.

PC1 gives a 'normal' report, I think, 4 packets out, 4 packets back in, etc.

I am not exactly clear what this can do, were you suggesting I try to 'ping from one computer to the other?

So what does this tell me?

Hello,

My ubuntu CD does have the Live CD facility, but It requires 256MB of RAM, and I have not yet installed an extra 128MB to the next slot.

I booted into 'safe mode', but I don't know what good that was supposed to do. When I checked out 'Network Connections', the page was blank. I suppose that makes sence, if the drivers had been deactivated by the 'safe mode'

I have run numerous 'Network Diagnostics', and they do not record any grading for the network adapters, that is they neither get a 'passed' or 'failed', nor was there a 'pinging' test done on the 'IPAddress', in fact the 'IPAddress' item was not even on the list!

Regards,

Chris B.

I have booted with the Ubuntu Live CD (after adding another 128 MB of RAM to the existing 128 MB), and although it showed my two ethernet devices in a working mode, it did not give me any information about network connection. I think I shall stick with Windows at this stage, better the devil you know! Unless someone has a specific direction they could lead me to in Ubuntu, that would give me an advantage in solving my problem, I will not go back there.

What about if I reinstalled Windows? Or 'flashed' the BIOS?

Sorry for the late reply.

were you suggesting I try to 'ping from one computer to the other?

Yes, I was. I assume what you did was ping each computer's own NIC? In that case, I would say there's something weird going on with PC #2. Are you sure there's no firewall running on it? Flashing the BIOS would also be a good idea.

Hello joeprogrammer,

What I did, was to ping from PC1 to the onboard network adapter of PC2, and that resulted in "Request timed out". Then I pinged to the new Ethernet Card on PC2, and that resulted in "Destination host unreachable".

Pinging on PC2 from both the onboard network adapter and the new Ethernet Card resulted in "Destination host unreachable".

PC1 can successfully ping itself.

Do the computers need to be connected to the internet to do these pings? I can't remember what the internet connection status was during the last test.

Pretty sure I have disabled all firewalls, but I will try that angle again when both computers are operating (at the moment I am converting PC2, a desktop, to run off 12 volts DC, and I am endevouring to reduce the noise of the CPU fan by temperature controlled fan speed).

Regarding the 'flashing of the BIOS', isn't that an undertaking that is potentialy fraught with danger? Any tips or precautions?

Thanks,

Chris B.

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