Why can't I see my network from a laptop?

[yalamo]

The wireless link in my home network has been working well for about 3 years, until last week. But now I have a strange problem.

I have an Edimax Broadband router. My PC is connected to it directly by network cable, and my wife's laptop is connected by WiFi to the router. The transmission is not encrypted, but I use the MAC address access control of the router to limit access to the network. Both our OS's are WIN XP SP2.

A few days ago, my wife told me she lost internet (my internet connection was fine). I looked at the list of available networks (apparently my neighbors'), and my router was NOT among them. I connected to one of the other available networks, and the laptop had internet and worked fine. I tried resetting the router, turning it on and off, shutting down her computer and turning it on, the same for my PC, all the combinations, but nothing helped. I couldn't see my router from the laptop, but did see the other networks Also bringing the laptop right next to the router didn't change anything, which indicates to me that there is absolutely no RF transmission from the router.

At night, we both shut off our computers, but left the router running, which is our usual practice, and I intended to buy a new router the next day. When we turned the computers on the next day, we saw that the laptop was connected to my network again, and I decided to wait till the fault appeared again before buying a new router.

Yesterday, the fault returned, but I found that by shutting off and turning on the laptop, everything worked well again. Today, the same fault happened again, and again shutting off and turning on the laptop seemed to bring my router RF back to life. This doesn't make much sense to me, and I still feel that the router is at fault. But before I buy a new router, can anybody out there reassure me that it's not the fault of the laptop?

 

[edfair]

From some past history I would suspect that it is a problem within the laptop. That for whatever reason it has decided to block data transfer to the one router.

 

[yalamo]

edfair, thanks.
What you say may be so. But why this particular router (mine)? How can I fix it? Where do I start?

 

[edfair]

start , programs, accessories, command prompt

ipconfig and see what you have presently

ipconfig release which wipes out the current

ipconfig and see what it reports

ipconfig renew

ipconfig and see what it gets back from the router

This is assuming that you get your ip address from the router using DHCP.
I'm not sure that the interim ipconfig will show anything useful. I've never done it.

If you are getting an IP address from the router your router is communicating and the issues are with the OS and the wireless and how they communicate with the router.

 

[yalamo]

Thanks again, edfair.

When I received your last post, everything was working OK. The laptop lost my router about a half hour previously, so I shut off the laptop and turned it on again, and as I say, it then started working OK.

I did the checks you suggested, with the system OK, so I don't know what they tell us.

The IP address comes from the router, as far as I can tell (It's the same address that I use as a URL if I want to "see" the router settings in my browser.) It turns to 0000 when I release ipconfig.

Also, when I release IP config, the wireless connection immediately shows up with an "x" in the system tray. This is not the situation when the laptop "loses" my router. After I renew IPConfig, everything is identical to what I had before the release. Also, the laptop "sees" the router as a wireless network again.

I have no idea what the significance of all this is. I'm just trying to decide whether to buy a new router or not. Can you tell me where to go from here?

 

[edfair]

Just a matter of trying to identify where the trouble lies. If you get a valid IP address while you are in the midst of a failure to connect other than DHCP it leads to a conclusion that the problem is local, not the router, and not the wireless.
This is because the IP you get uses the same wireless path.

It is not 100% certain, but at least a starting point.

 

[yalamo]

edfair, I'm posting to this thread again now because the problem I had didn't return until today.

I'm pretty sure it's my router that's at fault, not the laptop. When everything is working normally, ipconfig shows an ip address as 192.168.x.yyy which indicates it's getting the address from my router. When it's not working properly, the ip address is 192.168.x.zzz, which shows that it's getting the address from someone else's router, from whom I'm getting the internet connection.

Furthermore, when I look at my router diagnostics (from my PC which has a wire connection to the router) I see the MAC address of the laptop as an active DHCP client (as well as my PC) when everything is working well. When it's not working correctly, I only see my PC as a DHCP client.

Once again, I can fix the situation by rebooting the laptop. I assume that this is because rebooting causes the laptop to send a signal to my router to tell it to start transmitting (remember the router has MAC access control). If the router for some reason stops transmitting, the laptop automatically goes to the next available wifi signal in the area, and doesn't request transmissions from my router, so it simply won't turn rf on again.

Does this explanation make sense to you?

 

[rphips]

yalamo

Sorry to blast in here - First How are you doing?

Now laptops to not tell the router to start transmitting - the router is transmitting all the time. What is happing is you are using the MAC as a control. The laptop sends a notice to the router to let it connect - the router askes for the MAC address and the laptop gives it - and that has to be verified by the router - now, somewhere in this process the information is bieng scrambled thus when you restart it is getting resent.

First - go into your router and disconnect the MAC access controls and try connecting - If you are worried about security set the WEP keys and use that security.

MAC address security is used mostly for other devices that stay connected 24 hrs to each other such as Access points or other routers. A lot of people believe it is the best security but in reality your MAC address is broadcast alot out on the internet (example; banking, purchasing) so if possible use both. But since you are talking home I would just use WEP.

If you are still having the problem then the problem has to be the wireless card in the laptop. It Sounds like the wireless card is getting old and is starting to die. That could be the reason if you reboot your laptop you push some juice to it and it braodcast properly. If it is built in you can disable it and put in a wireless card.

Anyway its not your OS or the laptop or the router it is either a communication problem or your wireless NIC is going bad - so disable MAC access and let us know what happened.

Good luck, I hope this helps

 

[yalamo]

rphips, thanks for your answer, but somehow I still can't believe the problem is the laptop. (I tried disabling MAC access control; it didn't help.)

If the problem is a bad wireless card in the laptop, why is it that the laptop receives transmissions from other networks in the neighborhood (I can connect to the internet through them), but it doesn't even see my router in the list of available networks? About 5 networks show up on the list, of which two are unencrypted, but my router, which should have the strongest signal, is not among them? When everything is working fine, my router comes through loud and clear.

 

[N0ktar]

Is your WiFi network name unique or generic?
Have you tried updating the router firmware?
Does rebooting the router, not the laptop, fix the issue?
Have you tried resetting the router back to factory settings?
Did you try updating WiFi driver on the laptop as well?

 

[yalamo]

NOktar:
My WiFi Network has a unique name.
I once tried updating router firmware, Couldn't find any updates.
Restarting the router did not fix the issue.
I never reset the router to default settings; I will probably do it as a last resort before I get a new router.
How do I update a WiFi driver in the laptop? Quite frankly, I don't even know how to get to the WiFi card on the laptop - for all I know it may be part of the MB.

 

[G0AOZ]

The WiFi card in a laptop is often accessible through one of the removable panels on the bottom of the PC. It can usually be easily disconnected from the motherboard. If you do remove it for any reason, use care when pulling off the minature coaxial connectors for the antenna.

A quick look in Device Manager may well give you a clue as to make and model of the wireless device. Try the laptop manufacturer's website for updates, or go the supplier of the main chip on the WiFi card.

ROGER - G0AOZ.

 

[yalamo]

GOAO2, thanks - I looked at the device manager; the RF card is an Intel device, probably part of the motherboard itself - I haven't checked yet. Right now, everything is working again, so I'll wait till the strange fault occurs again before checking device manager again.

This may take some time - I'm leaving on a trip for about a month, and taking my wife's laptop with me (she'll use my PC). We'll see if I have any problems with it when I'm away.

 

[BionicJohn]

Try this if you haven't already.

Control Panel -> Network Connections, right click on Wireless network connections, Properties.

On the Wireless Networks tab, under preferred networks, select any network which has "(Automatic)" against it and click "Remove". Click OK, and then re-boot the laptop.

The computer will re-search and should find your local WAP.

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