I connect my PC to the internet via a power-mains connection then a cable to my PC. For the last 2 days, I could not connect to the internet so I though it was just my router acting up. I reset the router, reset my PC, checked my cable connections, nothing worked. I knew it was not my router as my cell phone and other PCs could surf the net fine. I plugged in my wireless USB adapter and I could connect to the net again.

I suspect my network port has gone bad.... anybody got suggestions on how to test and fix this? Or is this my mobo saying it's time to buy a new one?

So the network card on the motherboard is bad you are saying?? Well I would check in Device manager and look to see if it is even detecting it and all.. are the lights on it lighting up??

Are you on windows 10?

Still on Win7, not changed anything on my setup.

According to my son, the lights are still flashing on the back of the PC.... can't get to it at the moment due to all the junk I need to move. The device has been disabled on Device Manager but I did this manually after it wasn't working and I had to use the wireless USB adapter. I re-enabled it now and it still says I'm on an unidentified public network.

When I plug in my wireless USB, it automatically recognizes my home network and connects me to my router and to the internet.

A good test could be to load a Linux portable distro on a USB drive or DVD and boot with it and see if it gets detected and if it connects to the Internet.

Network ports very rarely go electrically down (i.e., mechanical or wiring problem).

Give us a screenshot of your IPCONFIG /ALL and a ping to your gateway/router IP.

It's rare unless you had a power surge.

In FL, it's not rare enough thanks to our frequent lightning.




The Jedi Master

Well, I think it is working, but it connects and ID's it as an "unidentified public network"....

After running IPCONFIG /ALL, I noticed it connects to an IPv4 address of 169.... instead of the usual 192.... IP address. How do I change this? My PC is hard-wired to one of those power-mains adapters.

Here's my ipconfig /all result with just the hardwire connection on. I cannot force it to renew the IPv4 address even with /renew /release or even netsh commands.

Sounds like its directly connected and the router is like on DMZ mode (passthrough) or bridge mode but your not on the DHCP part of your router. Try Resetting your router back to factory see what happens

It's auto assigning an IP to that port itself (the pc, not the router). It's not finding the router since it's on a different network. Note that there's no gateway IP (that would be the router IP), and the subnet should be 255.255.255.0 by default on a home network.
Also, your DNS servers listed are IPv6. You want that the same as your gateway (the router).

Go to your network settings, right click on the adapter.
On the list of options, go to Internet Protocol version 4 (TCP/IPv4) and click to highlight....it should already be check marked
Click change settings of this connection, or might be under properties
Select "obtain IP address automatically" and "obtain DNS server address automatically"

If you have a tab for "alternate configuration", make sure it's set to obtain automatically.

Click to highlight IPv6 and uncheck it.

OK

Reboot

See if it connects.

If not, go back in to the configuration for IPv4 and manually assign Gateway as the router's IP. Pick an IP in the same network, such as if 192.168.1.1 is your router, try 192.168.1.150 for the device IP. Subnet mask 255.255.255.0

Okay, Kryptonite wrote 99% true, but I'm a Datacenter Network Engineer, so I can be a bit more precise

There is no point to check "obtain IP automatically" and "obtain DNS automatically" since what you are seeing here is a PC who has already tried that but not found it's DHCP server. The 169. something range gets assigned if the NIC is set for DHCP but can't find a DHCP server. No point in doing that setting.

The reason it doesn't find the router is not because it's "on another network" but because either the link is dead, or the router is not acting as DHCP anymore.

Since the card doesn't show "Media disconnected" a physical break is still possible but very unlikely (that would mean cable or NIC broken).
OTOH it's interesting because if the router stopped doing DHCP then your wireless adapter and your cell phone wouldn't work with it either.

Next thing to try as Kryp already said is: If you know your home network settings (you can get them from the wireless adapter while you are connected) then set the IP manually on the NIC. It will be some 192.168.x.y address, and a gateway in the same area (usually 192.168.x.1 or 192.168.x.254). Don't use the exact same IP from the wireless, use something with the last digit +50 or so (i.e. if on wireless you get assigned a 192.168.1.3 then go for 192.168.1.53).

So basically something like my own setup here:




Subnet mask for such a home network always 255.255.255.0 as Kryp said. Disabling IPv6 is recommended but not usually a cause of this particular kind of problems.

Your goal now is to get the router and the PC on the same network again, up to the point where you can "ping router IP" and get a reply.

If you're really out of your depth here I might be free tomorrow evening and we could maybe set up some kind of teamviewer session.

Okay, did that and even put in the DNS Servers manually. Here's the pic:




Still no joy in connecting.

That all looks good Ice.

More things to try -

Ping the loopback address - this can tell you if the card is bad:

Ping 127.0.0.1


Ping the gateway (if you haven't already):

Ping 192.168.0.1


replace DNS servers with different ones, sometime you will be connected but your DNS server are not name resolving and it will appear that you are not connecting:

Google -
8.8.8.8
8.8.4.4

OpenDNS-
208.67.222.222
208.67.220.220


If none of that works you will need to look at the physical connection or what we call Layer 1. If you can string a new wire between the router and NIC card do so, otherwise check the connections. You can also download updated NIC card drivers on another pc and copy them and update.

Sometimes the NIC does go "bad" but still shows lights and appears to work, but doesn't pass packets. Rare but it happens. You may have to put a PCI NIC card in to get back to gaming..

Hope this helps in some way..

Just read through the post a little closer this time - What are the "Power Mains?" Is it one of those setups that use your house wiring to make connections across the house? If so they are notoriously finicky and I would start the troubleshooting there.

Move the pc to where the router is and directly connect it to see if that device is the trouble. Sounds like a pain I know but cheaper than buying parts..

Well, I pinged 127 and 192 and both are good. Not sure what you mean by replace DNS servers....

Power mains --- basically, I plug one device into the power socket near the router, hard-wire the router to that, the plug another device into the power socket near the PC, and run a cable from that to the PC...

Trying to troubleshoot via the Troubleshooting > Network and Internet panel and is says my Local Area Connection doesn't have a valid IP configuration and my default gateway is not available.

I tried changing the DNS to 8.8.8.8/8.8.4.4 and no joy.
I tried the DNS blank, no joy.
Putting in 208.67.222.222/208.67.220.220 gave me the old 169.254 IPv4 address but still no connection. Troubleshooting doesn't give me the valid IP config error now, but still says default gateway is not available.

have you reset the router yet>?

and by reset i mean putting a pin in the little hole on back to take the router back to factory defaults.

I really don't see the need to reset the router. 3 other PCs, 3 mobile phones, an iPad, and visitors can connect to the router (wireless) just fine. Am I missing something with a hard reset?

Reset or see if there's an option to restore in the router config.
If wireless is fine, even on this pc, but wired is having issues, he's saying maybe a setting is incorrect or corrupted.
You can save the configuration first if you have a bunch of port forwarding and rules set up, in case it doesn't work. There will
be an option to save it on there somewhere.