4

First off - I was eventually told to post here by a user on another SE site after several users had downvoted me with no explanation until one finally was kind enough to explain that I'd misunderstood the site's description. So if this is not the right place either then please tell me where it should go first, before downvoting for it being in the wrong place.

The environment

Win 7 PC connected by cable to a ASUS router on a wired LAN using DCHP. Machine used primarily for programming. A few days ago I removed another win 7 machine from the network and replaced it with a win 10 machine, which works fine, as did my Win 7 machine afterwards.

The problem

Recently while logged into my router from my Win 7, I saw that Internet was shown disconnected, although I was still able to browse to fast updating sites such as the BBC.

I reset the router just in case (as I have done many times before) but a short time later found my PC would not connect to the router or LAN at all.

The network adapter card reports that it is working correctly and I have flashing lights at the socket. I can ping localhost but pinging the router's default gateway results in timeouts. Network and sharing reports that it can't identify the problem but as expected ipconfig shows no default gateway and the generic IP address.

IPconfig /all reports

DHCP enabled Yes

Autoconfiguration enabled Yes

Autoconfiguration IPv4 address 169.254.254.158 (Preferred)

Subnet mask 255.255.255.0

Default Gateway (this is blank)

DNS servers all fec0:0:0:ffff

Things I have tried

  • Used a RJ45 cable tester on the cable to eliminate cable issues - all pairs are fine.
  • Plugged my laptop into the same cable instead of my pc to eliminate the pc - laptop connects to the network and internet ok
  • Changed the router for a different one to eliminate the router - laptop connects, PC still doesn't.
  • Disabled the onboard network adapter and inserted a new PCI NIC with freshly installed drivers instead to eliminate adapter HW issues. Still no connection, same, non working, symptoms.
  • Took out new PCI adapter, re-enabled on board one and restored my entire HDD from an image backup from several days ago before any issue started to eliminate software or driver issues problems. - exactly the same, non working symptoms
  • Disabled the onboard adapter again and reinstalled the PCI NIC and drivers with re-imaged HDD. Same, non working, symptoms.
  • Disabled the BitDefender AV - same issues.
  • Checked router via my laptop, all looks in order except that my old PC name is missing from the dhcp client list (as I would expect).
  • Changed to a static IP address and entered the default gateway manually in both adapters separately with the other one disabled. set up the router to accept that static address - no difference. Changed it back to dhcp again as it made no difference.
  • Removed the Win 7 PC from the homegroup and made sure the profile is home/work.
  • Removed the new win 10 machine from the network
  • Numerous times I've reinstalled the drivers, ran ipconfig /flushdns, nbtstat -RR, netsh int ip reset, netsh winsock reset, ipconfig /release,ipconfig /renew, turned off router and pc for an hour and restarted etc.

Now the last thing I've tried - wireless

Disabled all network adapters and installed a new usb wireless dongle with new drivers. It found the signal and the network, allowed me to log into the network with my password and shows good signal and link quality. However the dongle's ip address is set to 169.254.42.249 with a subnet mask of 255.255.0.0 and a gateway of 0.0.0.0. Hence I still cannot ping the router via the wireless card either and of course cannot reach the internet. Renewing my IP address just gets the same values again!

So I think I have eliminated the cable, router, on board adapter, NIC and any driver issues.

I've slightly given up now assuming a motherboard issue. Is this possible? Everything else is working fine.

I've now ordered a replacement PC but being a programmer there is a lot I need to get off my old HDD so getting the old machine working over the network would be a great help.

Is there anything I've missed or any reason for this error that I haven't thought of?

More info - wireshark

Running wireshark and capturing the pci nic I can see incoming packets from other machines and can see the router scanning to see which device has which IP address and that device replying, although clearly it does not get a reply from the win 7 machine as its default ip address is 169.254.245.158 as its not getting one from the DHCP (using dhcp with no static IP set up). At one point I can even see an outgoing request from the NIC (from the default address of 169.254.245.158) to address 169.254.255.255 with my computer name in it using the browser protocol. Although I don't know at which physical point wireshark intercepts the traffic.

in response to a comment The local router's lan IP is 192.168.1.1 (that's what I can reach from my laptop but not from the PC) DHCP IP poll start 192.168.1.2 DHCP IP pool end 192.168.1.254 Lease time 86400

After setting up a static ip in the NIC , the router allows you to assign that static IP address to the MAC address of the NIC. I've done this in the past and one of my laptops has such a static IP set up at the moment (working fine).

After having it fail using DHCP I set up a static address of 192.168.1.101 in the NIC. Still no connection. Then I set up the corresponding static address in the router in the same way as the laptop (which is 192.168.1.100)but it made no difference whether dynamic, static with just the NIC set up or static with both nic and router set up.

What is puzzling is why anything should have changed. Its been working fine continuously for about 5 years. Apart from rebooting the router when I noticed while logged into the router from my pc (which I only did out of interest to check it had picked up the new machine) that the router's network map indicated no internet, I've made no changes to the networking side for years until trying to resolve this lack of connection.

I'll try to add screen shots

LAN IP

static ip addresses on the router

and here is the full dhcp list - Note that the PC 192.168.1.101 is not showing but the laptop 192.168.1.100 is enter image description here

Improve this question
10
  • Add in your router's local IP config, and what static IP you attempted on your machine in your 9th bullet. The more details, the more help you'll get.
    – mfinni
    Commented Jun 25, 2020 at 17:46
  • Also please give some more details around "set up the router to accept that static address" - that shouldn't be a necessary step for a network. I'm thinking you may have configured something in the router that you didn't mean to and that's what messing you up, so I think the whole picture will help.
    – mfinni
    Commented Jun 25, 2020 at 17:48
  • Do you see incoming DHCP offers using Wireshark, or do you only see outgoing discovers/requests? (I'm somewhat surprised installing a new PCI NIC didn't help, since my main guess would have been that your Ethernet chip simply fried itself...) Can you try booting a different OS entirely, e.g. Ubuntu off a flash drive, and see if it works there?
    – grawity_u1686
    Commented Jun 26, 2020 at 11:07
  • I can see outgoing discover requests but no response. I tried booting from a cd into windows pe but still no connection. I also started in safe mode with networking and still couldn't ping the router. I'm also surprised the new nic didn't work as I assumed a dead motherboard adapter when the more obvious fixes didn't work in the first place. Rather disappointed when that didn't work either...
    – user2834566
    Commented Jun 26, 2020 at 11:45
  • First - check the voltage output of the asus router power supply - they tend to be odd voltages - my rt-n66u was 18v, but the power supply failed but the router still worked (badly) on 12v. Second, test or replace all network cables. Do you have a USB ethernet adapter to try?
    – JohnnyVegas
    Commented Jun 26, 2020 at 16:50

1 Answer 1

Reset to default
-2

yo dude open cmd.exe as an admin and type this netsh wlan set autoconfig enabled=yes interface="Wireless Network Connection" or "Wi-Fi"

Improve this answer
2
  • He already tried resettten just about everyhting he could. And the primary problem is the wired interface. The Wifi adapter was only added AFTER for troubleshooting so that automatically started in a fresh config.
    – Tonny
    Commented Jul 4, 2020 at 22:56
  • @c001 dude Thank you for your suggestion but it would be unwise of me to simply execute a command suggested by someone without them also explaining what the command does and what I should expect to achieve by running it. After all, if someone suggested I open cmd.exe and run "format C:/fsNTFS/v:C/q" I expect it would make my network problem go away - along with everything else. (I'm sorry some other users have chosen to downvote a brand new user with no helpful reason why, but there are some unkind, self important people on SO who have forgotten what it was like to be a new user themselves.)
    – user2834566
    Commented Jul 6, 2020 at 9:56

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