Windows 7 Limited Access Wireless Network

[Synergy Computer Repair]

One of my weaknesses is my networking skills. I am looking to get a bit of info on a problem I encountered yesterday at a job.

I had a Windows 7 Pro machine that needed a wireless card added to it. I installed the card and drivers. The network was discovered and I connected using the WPA2 password.

It displayed that the network was connected but had limited access, signal was good ~80% strength. So I tried the following:

Released the IP and renewed
Restarted the router
Released the IP and renewed again
Restarted the PC
Deleted the network from "Manage Networks"
Ran ipconfig /all and noticed there was no Default Gateway designated

So I reset Internet Settings, and checked the TCP/IP v4 settings and they were set to automatically obtain on both DNS and IP Address. Restarted. Still nothing.

So I copied my smart phone's default gateway, which was connected to the internet via their router.

I set the IP config to manual and added the IP, Subnet Mask, Default Gateway, and DNSs and the internet worked. Although the network still said there was limited access.

I would like to know why this happened and what i could do in future to resolve it.

Cheers

John.

 

[datagnostic]

It's good that you tried with the manual IP configuration, because you can know rule out that there's anything wrong with the association and authentication process.

Was the computer assigning itself an APIPA address? That should be in the 169.254.0.0/16 range.

If it did, that would indicate there's a DHCP-related problem. You will find traces of evidence in your event viewer if this happened.
You might find other indicators as to what the problem was too.

Did it still say "limited access" after a reboot also, because it's not always immediately correct

 

[Cambridge PC Support]

I presume your smartphone managed to successfully get a DHCP-assigned address and worked on the 'net OK?

 

[Synergy Computer Repair]

I don't know about the APIPA address, there was an address assigned under the wireless connection in ipconfig, the format was something like 169.254.x.xx - yes.

Is DHCP a client side problem or a router issue?

I spoke to a friend about this and mentioned that it could have been an issue with the AES / TKIP - is this relevant?

Yep Kev, the Android was having no issues, nor was the Windows Vista laptop I took with me - both worked perfectly. Nice to be speaking with someone from the local vicinity!

 

[datagnostic]

I don't know about the APIPA address, there was an address assigned under the wireless connection in ipconfig, the format was something like 169.254.x.xx - yes.

That's an address Windows (amongst others) assigns itself when it couldn't get an IP from a DHCP server.

Is DHCP a client side problem or a router issue?

Could be both, but since the wifi works on the smartphone and the other laptop I'd lean towards the client.

I spoke to a friend about this and mentioned that it could have been an issue with the AES / TKIP - is this relevant?

Those are the encryption techniques. If they weren't right, you wouldn't have been able to connect. Most routers have the option to run both simultaneously because some -older- devices can't handle WPA2 with AES.
If you double click the network to connect, it should get these parameters from the AP automatically.

Yep Kev, the Android was having no issues, nor was the Windows Vista laptop I took with me - both worked perfectly. Nice to be speaking with someone from the local vicinity!

Then it definitely looks like a client issue. Check the event viewer for clues! Have you tried temporarily disabling the onboard FW?

Good luck

 

[Synergy Computer Repair]

Thanks for that detailed response datagnostic.

Unfortunately I am not infront of the PC right now but the customer needs me to do some more work for them next week so I can look again when I am there.

With regard to the firewall, I will check that next time I'm there.

 

[Cambridge PC Support]

I'm feeling lucky, 50p says that it's Norton deeming DHCP a threat and blocking it!

 

[Synergy Computer Repair]

Ohh tough luck Kev. There was no Norton, and if there was there wouldn't be after I'd be round to look at it.

 

[Tepin]

I would recommend running Farbar Service Scanner on the machine when you are their next week.

http://www.technibble.com/fabar-service-scanner/

 

[Mr.Mike]

Have you tried resetting the router?

 

[Synergy Computer Repair]

Morning Chaps

ScarletPathos: Router hasn't been reset, just restarted, as the customer had a lot of problems and had BT out on a number of occasions I didn't see it necessary as my phone and Vista laptop was working just fine.

Tepin: I will definately have a look at that tool does it just report its findings to a log or does it give you an idea of what is actually wrong?

I love these little lightweight programs like unhide, rkill, combofix, and now FSS.

Thanks for the suggestions.

John

 

[Martyn]

I always carry a couple of Edimax wireless dongles. They cost under £10 from Amazon. Try one of those and go from there.

 

[quinnlaup]

You didn't mention if you tried safe mode with networking to see if it connects successfully? Also it might be worth changing the channel that the router is broadcasting on.

kind regards

quinnlaup

 

[Tepin]

The tool gives you a report that includes things like the status of networking services and an MD5 hash check on related system files. If the DHCP service isn't running for instance it will be stated in the report. If the cause is missing/corrupt system files it will usually detect it and if it's a missing/corrupt or disabled registry key it notifies you of that as well.

From there it's a matter of either restoring the corrupt files or repairing/enabling the right services in the registry. There is also a link in the comment section of the page I linked that has .reg patches for network registry keys if that looks like the cause.

I found this tool to be invaluable when the ZeroAccess rootkit first hit the scene and removal tools weren't repairing the OS properly. I'm not extremely knowledgeable about networking either but using this utility while working on those infections improved my understanding a lot.

 

[datagnostic]

Also it might be worth changing the channel that the router is broadcasting on.

Only if you're 100% certain interference is the issue You can use InSSIDer to determine the ideal channel. It will also tell you the exact RSSI and SNR and some other security-related settings.

 

[Synergy Computer Repair]

Thanks guys I'll get myself a copy of InSSIDer and FSS and see how I get on.

Thanks again guys. Good hustle.

 

[brock029]

I always carry a couple of Edimax wireless dongles. They cost under £10 from Amazon. Try one of those and go from there.

I second what Martyn said...Just to make sure it is the computer and not the new wireless card you installed.