Wireless network dropping off

I have a 3Com Wireless router. Bought it on Komplett for €99 about a year ago. I also have NTL broadband which I don't have any issues with. Anyway...just wondering (without having done much googling on the subject) if people have any resolutions to the network dropping off on wireless networks. Seems to happen at random times. Is it the router? My laptop? Any way of finding out?

Interesting, I've started having the exact same issues just in the last 10 days but with Netgear wireless router that NTL provided themselves. I randomly need to turn off both the modem and router and back on again for the network to return.

Herb said:

Interesting, I've started having the exact same issues just in the last 10 days but with Netgear wireless router that NTL provided themselves. I randomly need to turn off both the modem and router and back on again for the network to return.

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Could it be interference from a neighbouring wireless LAN? Are other network ids appearing when you do a scan? If so, you may need to change the default channel on your wireless router.

MonsieurBond said:

Could it be interference from a neighbouring wireless LAN? Are other network ids appearing when you do a scan? If so, you may need to change the default channel on your wireless router.

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Interesting...I have loads of wireless networks around me. Never thought of that. I'll try this later.

I never have to restart the modem (only had to a handful of times). It usually just requires a laptop reboot to be able to see the network again.

Try running Netstumbler to see what other wireless LANs are in range and change channel on your router/Access Point if necessary. Note that only 802.11b/g channels 1, 6 and 11 are considered non overlapping (even though they still do) so having your's on channel 5 and the neighbour's on channel 6 (for example) will still mean significant interference. See Wikipedia for more on this. If your microwave is used a lot then it might be worth checking the unit for the specific frequency that it operates on and then choosing an 802.11 channel as far from that as possible (e.g. my microwave operates on 2450GHz so I chose a channel away from that to avoid interference. Obviously any other 2.4GHz band equipment in your home (some baby monitors, some cordless phones, Bluetooth devices etc.) may also interfere with your network.

Another thing to check is if there are any driver or firmware updates for your 802.11 equipment that might address outstanding bugs and interoperability problems.

One basic thing to check is that the wireless router is suitably located for best coverage (e.g. not unduly obstructed by shelves etc. and usually at a high point in the house.

Thanks for that Clubman...will look into all that later when I get the chance.

Think location is good. It's in the centre of the house (in my bedroom) but good coverage throughout house.

Is this a recent development - i.e. was it working fine before but has recently started exhibiting problems? Can you clarify what you mean by "dropping off" (e.g. connection to router breaks and needs to be reestablished or the throughput slows down or something else)? If it's a recent development then obviously the first thing to look for would be changes to the local setup/environment (both in your own house and in adjoining houses) such as the addition of new gear etc.

Another useful tool for diagnosing problems and monitoring network (wired and wireless) setups is Ethereal but (at least up to recently - haven't used it for WiFi sniffing in about a year) only certain wireless WiFi chipsets/cards/drivers work in the required monitor/"RFMON" mode and none in Windows (e.g. you have to boot into something like Kanotix GNU/Linux to do WiFi packet sniffing).

Kismet might be another option for diagnosing problems but I haven't used it at all yet and I think that the same caveats applicable to Ethereal apply here too.

Netstumbler is simple to run even for novice users. Ethereal arguably requires a bit (lot?) more technical expertise.

No...has been happening for the length of time I've had broadband.

Two things happening:

1) Network still connected but can't connect to internet. If I disconnect from the network and re-connect it can work. Restarting always works.

2) Network just drops - disconnects itself. Can't connect to router console. Again...sometimes you can reconnect. Sometimes it refuses to reconnect and I have to reboot.

Have you tried checking the following details when these problems occur (in a DOS command shell):

• ipconfig /all (to see what the network settings look like)
• ipconfig /renew (and see if this fixes the problem)
• tracert www.google.com or ping www.google.com (to see what sort of routing is working)

Basically this sort of stuff is looking at the general TCP/IP setup to see if there are problems at that level as opposed to at the actual physical link (WiFi) level.

same thing happened me, has 12 calls to dell and they finally sent me out a box for CAR.

I then changed the encryption on the router (and subsequent the laptop obviously)from WKA to WEP(i think, ill check 2night) 8 bit, issue disappeared!!

Apparantly this is a windows problem, not a hardware problem (not sure if either are relevnet to yours but tis a simple thing to try, even if only to rule out! )

drop-d said:

same thing happened me, has 12 calls to dell and they finally sent me out a box for CAR.

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What's CAR in this context?

I then changed the encryption on the router (and subsequent the laptop obviously)from WKA to WEP(i think, ill check 2night) 8 bit, issue disappeared!!

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I've never heard of WKA or WEP 8 bit - do you mean they switched from WPA to WEP (64 bit - actually 40 bit, or 128 bit) or something like that?

Apparantly this is a windows problem, not a hardware problem (not sure if either are relevnet to yours but tis a simple thing to try, even if only to rule out! )

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What is a Windows problem? Certainly not WPA incompatibility in general since I have successfully used WPA (TKIP) with many routers and Windows platforms. Maybe you could point to more authoritative information about the alleged Windows problem to which you refer?

I had a problem recently where Skype would go slightly bananas on my laptop and cause the network connectivity to appear to drop. It was intensely frustrating trying to find out what was causing it. Basically I would be broswing away and then suddenly I couldn't browse, yet the wireless link was still up and I could ping hosts on the internet no problem.

When I tried to ping by hostname it would fail, but pinging by IP address worked. When I tried doing any DNS lookup it would fail.

I ran ethereal and saw that my machine was issuing many thousands of DNS lookups for what were (to me) random hostnames. Turn off Skype - DNS lookups stop. Turn on Skype - DNS lookups start again.

I think what happened was that the DNS server I was connecting to was limiting my DNS access rate because it suspected a denial of service attack. Either way, I was not very impressed with Skype.

I could also normally resolve the problem in the same way by removing the network card and starting it up again. This of course had the effect of knocking Skype off (because it had no IP address to bind to any more) and so indirectly resolved the issue.

If you run Skype, try turning it off and see if the problem persists. Also, try ethereal as outlined by Clubman above - if you see tons of DNS lookups then you may have the same problem as me.

z

Thanks Zag. Use Skype in work all the time. Have about 17 windows open as we speak

Don't use it at home though (yet) so it's not that. Clubman has given me a lot to work with so if I get outta here at some reasonable stage tonight I'll try to diagnose the problem later.

By the way...just going back to earlier conversation...my network is WEP encrpted.

ClubMan said:

What's CAR in this context?

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Collect And Return

ClubMan said:

I've never heard of WKA or WEP 8 bit - do you mean they switched from WPA to WEP (64 bit - actually 40 bit, or 128 bit) or something like that?

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wka = wpa sorry, one of the joys of dyslexia and WEP 8 is 128bit, abbreviation!

ClubMan said:

What is a Windows problem? Certainly not WPA incompatibility in general since I have successfully used WPA (TKIP) with many routers and Windows platforms. Maybe you could point to more authoritative information about the alleged Windows problem to which you refer?

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A software issue ( windows management) between the internal wireless network car and the router can exist in exceptional circumstance. There is a workaround, but its not 100% fixable and relates to the power setting of the wireless card.
I was referred by dell technical support + microsoft.....so apologies if a) i didnt answer accurate enough for you (i dont work in dell or windows technical support) and b) you dont believe me, you can find plenty of information on both their websites!
There are many different issues clubman, just cos you never came across it hardly implies it doesn't exist....i was only trying to help!

I never said that I didn't believe you. Your earlier comment that "apparently this is a Windows problem" seemed to suggest that "this" meant Gabriel's original problem of the WiFi network dropping off and I was merely pointing out that this is not totally correct and that Windows does not have any fundamental problem with wireless networking in general as you seemed to suggest, whatever about other very specific problems that it allegedly has in this context.

i gave an example of my issue.
i asked if he had WPA encoding, as i was told by dell technical support there is an inherrent windows problem.

again,
i didnt say that i knew what his problem was. (that should have been apparant by me asking him for more information )
I said i have the same symtpoms.....and gave him the advise given to me!