Laptop cannot be accessed ONLY on one specific wifi network

[rlincolnh]

Short version:

I have two wifi networks on my main W7 desktop.
I used an old XP laptop as the "Setup Device" when configuring a new Netgear EAX20 as an extender for one of those networks.
Everything went well until the final step, which failed. Now the laptop is somehow prohibited from accessing, or being accessed via the wifi network that I was extending.
Yet it operates perfectly well on my second wifi network.

All other devices in the house continue to operate without problems on the "prohibited" network.

Further information:
I've been chasing this for nearly a week, checking and double-checking all the myriad solutions for lack of connectivity, all with no effect.
When I connect on the "prohibited" network, the DHCP server in my main modem/router gives it an IP immediately, and it immediately appears under the 'Network' icon in Explorer.
As I said above, if I connect the laptop to my second wifi network then there are absolutely no problems of any sort. All laptops and the W7 desktop can see each other, share workgroups, etc, etc.
Also, if I connect it by cable, then it's all ok.
All other devices in the house (laptops, tablets, mobile phones, etc) continue to operate normally on the "prohibited" network. It's just this one that has problems.
I re-installed the wifi driver in the laptop yesterday (desperation!), but with no effect.

The simple solution would be to simply reinstall the OS. But this problem has really got hold of me now. I want to know what could have been done (presumably by the failed Netgear setup operation) that would restrict a machine from working on a specific network.

All suggestions gratefully received.

 

[file3456]

So what was the final step you had to do?

When you say can't connect to network, do you mean the WIFI its self from the extender or a Windows network share? If it's WIFI I can offer some help, Windows share stuff I don't personally mess with. Samba and NetBIOS is risky biz in my computing world. I use a local in-house FTP server for data transfers. One day I'll migrate to WebDav. Anyway...

If this is a WIFI issue, try this in the XP laptop. How to remove existing wireless network profile in Windows XP | TP-Link

 

[samuria]

Open a cmd prompt type


ipconfig /all


do on the problem pc and one on the bad network working post results

 

[rlincolnh]

Thanks for replying, guys.

F22: Here is a link to Netgear's setup procedure

How do I set up my NETGEAR WiFi range extender? | Answer | NETGEAR Support

I executed down to and including step 14. Step 15 failed (it eventually defaults to a Netgear page that tells you that something has gone wrong, and you are not actually connected to your extended network).

I have (many times during the last week) been through the procedure in your link. Yes, it eventually says "connected", and "Limited or no connectivity". The DHCP server immediately gives it an address, but that's as far as it goes. You can't even ping it (times out).


Samuria: Here are two files for config/all. The first is from a Vista laptop that is happily connected to the network, the other is from the troubled XP laptop.

View attachment Vista_config_good.txt

View attachment XP_config_bad.txt

 

[file3456]

SO if I'm reading this right. IN step 14 you should connect to the extender network. I'd use the other computer or a phone. Then click continue in the browser in XP that you used to setup the extended network. But I think the key thing here is that a device needs to be connected to the network FIRST before you click the continue button.

The other thing here is that you can configure all this with their Nighthawk App. It's basically the same thing only in App form rather than from a browser. How do I install my extender using the NETGEAR Nighthawk App? | Answer | NETGEAR Support

Why they use a website to configure this I don't know. In the good ol' days you just logged into the interface via its local IP address. I guess companies are now trying to make it "easier" for setup. I think that adds too many bolts to a simple machine and I smell a hack potential with it.

Make sure your firmware is the latest. EAX20 | WiFi Range Extender | NETGEAR Support

 

[rlincolnh]

"In the good ol' days...". Computing was a lot easier 50 years ago. As you say, simply logging in to the new device and setting up a few parameters is the way to go. With devices having so much internal compute power and local storage, the setup procedure can be made very pretty, and simple users can easily be presented with a few yes/no/select options that will suffice in 90% of the cases.


When I get around to setting up the EAX20 again, I'll make damn sure that I'm connected on a different network than the one that I want to extend.


But in the meantime, "I really want to know what could have been done ... that would restrict a machine from working on a specific network."

 

[file3456]

When I get around to setting up the EAX20 again, I'll make damn sure that I'm connected on a different network than the one that I want to extend.

I don't think that should be done. Just use a smartphone with the Nighthawk App on the network you plan on adding the extender to.

But in the meantime, "I really want to know what could have been done ... that would restrict a machine from working on a specific network."

On its face it seem like a routing table mess up of some sorts in the extender. You get an IP from its DHCP so that's not a problem, but it seems there's no Internet capability.

 

[rlincolnh]

On its face it seem like a routing table mess up of some sorts in the extender.

But note that the extender is no longer in the picture. It is currently packed away in its box, so we now have just the bare-bones network - a W7 desktop, the Sagemon Fast 5355 router/modem, and a couple of laptops (XP and Vista). The Vista one works, XP doesn't... except that it does if I connect to a different wifi network.

 

[file3456]

To see if my assumption is correct, hard reset the modem. You'd press and hold the reset button for at least 7 to 10 seconds. You will need to bring your settings back.

 

[rlincolnh]

Yes, I was going to do that a couple of days after the problem developed, but when I went to save my settings, I discovered that the current version of the firmware doesn't allow you to save them! So I haven't done it, and probably won't for a while yet. I have checked to see if the XP Wifi MAC address was being filtered, but the table is empty, if that's the sort of thing you were wondering about.
I agree, resetting the router/modem may well turn out to be the most straightforward way to cure the problem, but, if it is at all possible, I want know why it doesn't work. It's close on twenty years since I did any significant Ethereal work, but given the capabilities of Wireshark these days plus the fact that I can create several different network configurations that do/don't work, I think it could make an interesting project.

I'd like to thank thank you for your interest in my problem, F22. I will continue to monitor this thread, so if you have any brainstorms in the future I would be very pleased to hear them. In turn, if I make any notable progress, I will post it here.

Thanks for listening.

 

[file3456]

I highly doubt Wireshark will tell you anything. That just captures packets, and well, there is no Internet to capture packets. You'll see SSID requests and what have you though I'm sure. The lack of Internet to me seems indicative of a router/modem issue. I can't remember if XP does this or not, but it does in 7. What happens is that Windows will ping an Akamai CDN IP address and if that fails Windows assumes you have no Internet. Thus you will see in 7 or above an exclamation symbol over your network icon in the task bar indicating you have no Internet ability. With XP and it saying there is limited connectivity, I'm thinking maybe it's doing the same thing. I'd have to fire up XP in VMware again and monitor the NIC and see if it pings Akamai like 7 does.

I suppose the other thing that's withen the realm of possibility is that your XP computer has some form of network stack mess up that occurred while configuring the extender (repeater). I wouldn't think that would be the case though since I don't think a browser interaction with the extender's interface would touch the computer its self. But if you want to try this, use Winsock XP Fix and see if that solves anything. WinSock XP Fix - fix XP internet connectivity That program was a life saver for me back in the day when removing firewalls or an anti-virus would mess up the TCP/IP stack. I found it better at resetting the network stack than the plethora of Windows 7 commands of resetting the network stack that may not even fix the issue. Note, you can't run Winsock XP fix in 7 though, just making the comparison. Though, I may try it in VMware and see if the same values get reset or not or if it messes up the whole lot.

Thanks for listening.

I'm always listening... to the air waves.

 

[rlincolnh]

Some good thoughts there F22, but whether or not XP is trying interrogate an internet address, I think the problem is much closer to home. To reiterate the situation:

1. Once XP has made a connection to the router (however limited it may be), it obviously goes through the request/offer/accept protocol with the DHCP server in the router, and gets a local IP address. So at the hardware level, the link works.

2. Pings don't get through, neither W7 -> XP, nor XP -> W7. i.e. the problem is further up the stack...

3. If I connect an additional wireless router (actually an old Netgear CD6300 modem/router) to the W7 desktop, the XP will happily connect to it, and everything operates as though there isn't a problem in the world. Full local and internet access, everything. And everything else keeps running happily on the original network.

4. As an aside, if I cable connect the XP to the W7 modem/router (Sagemon 5355) everything is normal.

5. At this stage it seems reasonable to point the finger at the 5355, but there is nothing that can be seen (at the user level) that might be involved, and remembering that it has been powered off/on several times (although not a hard reset), there is still the question of how a failed EAX20 setup procedure could have screwed up the 5355.

6. Remember that a bunch of other devices (including the Vista laptop) all happily operate 24/7 on the same Sagemon SSID that causes problems for the XP.

7. I could try making the XP spoof a different MAC address ...

8. Hmmm... but now the wife wants to go out.... and it's Monday tomorrow .