Ethernet stopped working!

aliEnRIK

Tried flushing the DNS cache?

1. Click the start button and navigate to the command prompt (Start > All Programs > Accessories > Command Prompt)
2. Make sure that you right click on the command prompt application and choose "Run as Administrator"
3. Type in the command "ipconfig /flushdns"

I wouldnt completely rule out infection. If youve no security at all and you visited a hacked legit site then how would you know?

Toxteth_OGrady

BunShopBandit wrote: »

The OS is reporting that the media is disconnected, so that is pretty much what it believes.

That's the soft VPN adapter. The Gigabit NIC appears OK in IPConfig.

OP might want to try this. The GUI should be easier to follow than CLI but runs the same tools:

http://www.7tutorials.com/how-troubleshoot-network-problems

zudecke

debitcardmayhem wrote: »

Could you issue a netstat -rn , and see what you have

Could you please elaborate? I'm reasonably okay with computers, but I wouldn't say I'm very technical..

aliEnRIK wrote: »

Tried flushing the DNS cache?

1. Click the start button and navigate to the command prompt (Start > All Programs > Accessories > Command Prompt)
2. Make sure that you right click on the command prompt application and choose "Run as Administrator"
3. Type in the command "ipconfig /flushdns"

I wouldnt completely rule out infection. If youve no security at all and you visited a hacked legit site then how would you know?

I tried this and got the returned error:

Could not flush the DNS Resolver Cache: Function failed during execution".

Any other ideas?

Toxteth_OGrady

Try following the instructions in the link I posted at #14

zudecke

BunShopBandit wrote: »

So you appear to ping the local IP address OK (67)
But can't ping the gateway (254) or googles public name server (8.8.8.8).

The OS is reporting that the media is disconnected, so that is pretty much what it believes. I'd be looking at a flapping interface/bad lead to start the ball rolling.

The only fly in that theory ointment is that you appear to have been leased and IP via DHCP, rather than an autoconfig 169 address. So this either suggests that either it has managed to get a lease from your DHCP server (which if there is no connectivity is unlikely, if not impossible) - or it has cached it locally. May be worth releasing and renewing to see if it picks up the address again. Thing is, if it can't reach a DHCP server it *should* give it up, but I can't say for sure if Microsoft have followed the protocol to the letter, or assumed a 'no complaints, hang on to the IP' approach.

ipconfig /release
ipconfig /renew

I'd be thinking along the lines: faulty lead / socket | speed/duplex mismatch {normally reported} gb -v- mb | IPv6/IP4 settings or hardware/driver issues. For such occasions (which are pretty rare as the stack is Über reliable) I keep a USB Ethernet adaptor, just to isolate system board/NIC issues.

You can safely forget DNS issues, if you can't ping googles servers at 8.8.8.8 DNS is not going to be the issue. As for the ARP cache, it is a very slim possibility, but as arp results are (normally) cached for a very short time you'd pretty much need something running all the time trying to poison the cache (virus/malware etc) and you seem happy that's not the case. You can just check with:

arp -a

The nub of it - something has changed (or less likely - failed) - it looks like something is stopping either the mac address resolution at layer 2, or a complete physical/hardware failure | mismatch is to blame - assuming there is no infection/malware/firewall issue.

Good luck with it

Wow.. You know your stuff!

Erm.. Hmm..

Where to start? Lol.. The ipconfig release/renew - should that be done in "Run as Admin" mode, or normal CMD?

Toxteth_OGrady wrote: »

That's the soft VPN adapter. The Gigabit NIC appears OK in IPConfig.

OP might want to try this. The GUI should be easier to follow than CLI but runs the same tools:

http://www.7tutorials.com/how-troubleshoot-network-problems

What's "CLI"? Are you just linking me to a Windows 7 troubleshooting guide lol?

Toxteth_OGrady

zudecke wrote: »

Are you just linking me to a Windows 7 troubleshooting guide lol?

Why not take a look?

asbokid

Is the Realtek ethernet adaptor on the motherboard? Is it the RTL8167? What operating system is that? Windows 7? What is the router? It presumably doesn't support gigabit ethernet?

Could you try disabling autodetect and forcing the adaptor to use 100mbps ? Apparently in Windows, you need something like

Control Panel\Network and Internet\Network Connections .......
Right click adapter > Properties > Configure button > Advanced tab Speed and Duplex > 100mbps full

Have you tried powercycling the router?

asbokid

BunShopBandit wrote: »

So you appear to ping the local IP address OK (67)
But can't ping the gateway (254) or googles public name server (8.8.8.8).

For some reason, the OP has modified his original post, but his earlier cut-and-paste showed that he could ping the gateway, albeit with a 25% success rate.

The OS is reporting that the media is disconnected, so that is pretty much what it believes. I'd be looking at a flapping interface/bad lead to start the ball rolling.

The only fly in that theory ointment is that you appear to have been leased and IP via DHCP, rather than an autoconfig 169 address. So this either suggests that either it has managed to get a lease from your DHCP server (which if there is no connectivity is unlikely, if not impossible) - or it has cached it locally.

The OP has got (or had) intermittent connectivity, so DHCP might be a journey up the garden path.

May be worth releasing and renewing to see if it picks up the address again. Thing is, if it can't reach a DHCP server it *should* give it up, but I can't say for sure if Microsoft have followed the protocol to the letter, or assumed a 'no complaints, hang on to the IP' approach.

Even if Windows hasn't released the IP address back to the DHCP pool, depending on the model of router, pings from the PC should still be recognised and acknowledged.

There is the arping tool for Linux. I guess there's a similar MAC layer ping tool for Windows?

The nub of it - something has changed (or less likely - failed) - it looks like something is stopping either the mac address resolution at layer 2, or a complete physical/hardware failure | mismatch is to blame - assuming there is no infection/malware/firewall issue.

At this point, with the OP convinced that the cable (and router) are both okay, and with no more configuration options left to tweak in Windows, I would download a Linux live CD, boot from that and test the hardware with a known good operating system.

zudecke

Hi guys..

Interesting points.. Just remember that I have been using this desktpop and router/cable combination for 1 year straight and NEVER had any problems with speed, dropping connections, etc. Just suddenly, since I had to manually power down the machine after a crash on Saturday night, I have not been able to get internet.

Very sudden.

Could it be a virus? Is this heard of?

Toxteth_OGrady

Have you tried the Windows Network Troubleshooter? You seem reluctant to give it a go. It may or may not fix it or even give further pointers to what the problem is so surely worth a shot?