weird problem with home wifi

We have a friend staying with us at the moment. Whenever her computer connects to our wifi, the wifi starts acting really wonky. The signal is constantly dropping, then coming back, then dropping again. At first I thought it was just too many devices logged in at once, but this morning it was just my SO and my friend’s laptops, and the wifi was still acting weird. Then, once we took her laptop off the network, everything was fine.

Normally we have 2 laptops and a few other devices using the wifi at once, and it’s never been a problem. Is it possible that my friend’s laptop is messing up the wifi? Or is there something else that’s causing the problem?

This is a stab in the dark (SITD), but it could be the network settings in her laptop mean it’s not getting the correct address. Alternatively, the wireless settings may be interfering with your router. Check that her settings match or are at least close to yours.

Maybe an issue with 802.11b vs. 802.11g/n?


Is your friends laptop older than the other devices? If it is it might force the router to “speak” an older protocol, reducing its capacity.

A lot of routers will run at the lowest transfer rated device connected to it, so if your friend has a 802.11b connection, all your devices will connect at that connection rate. That could be causing the problem.

Actually, I think it might be the other way around . . . she has the newest computer out of all of us. I just checked my computer and it is a 802.11b connection. My SO has a b/g. Does it make sense that if she has a 802.11n connection, it would mess with the wifi for the other devices?

I will check her wireless settings once she gets home.

If her computer or the router is set to 2.4 GHz for both 802.11n and 802.11b, it may be dividing the wireless signal between the two when her laptop is connected. That could potentially halve both the bandwidth and the amount of interference-free channels available for all your b devices. Try turning off 802.11n on the router altogether, or switching it over to 5 GHz (if her laptop supports that).

Alternatively, does she use a lot of BitTorrent, Netflix, or other high-bandwidth applications? Some cheap consumer grade routers get overwhelmed with the sheer amount of traffic coming to and from multiple computers, especially if they connect to multiple peers like BitTorrent tends to, and eventually slow down or outright crash.

ETA: If you know anyone with an Android phone, they can download the Wifi Analyzer app and see what’s going on with the frequencies and channels. Sometimes just switching the channel can dramatically improve performance, especially in crowded neighborhoods. If you don’t have an Android phone, there are probably similar programs available.

My guess would be along these lines.

I once had a friend who was having all kinds of problems not only with his internet, but with his laptop, and he swore a “virus” was causing it. Turned out he had a BitTorrent client not only autostarting with Windows, but as a browser toolbar. That wouldn’t necessarily be a problem in itself, but being an avid user of BitTorrent while not really understanding how it all works and what’s going on behind the scenes, is just asking for trouble. Turned out he was seeding a metric crapton of stuff, which was everything he had ever gotten from torrents, since he didn’t know enough to realize that you can and should delete the torrents themselves after a while and you still get to keep the file. :smack: Of course, since it was autostarting, this was happening whenever his laptop was on - both bogging down his network AND slowing his laptop down to a crawl in short order.

Also along these lines would be that her computer is infected with worm or Trojan and being used to push out a lot of spam or some other bandwidth hogging events.

Your friend’s laptop isn’t set to a static IP, is it? The router almost certainly assigns IPs on a “first come, first serve” basis. Let’s say all devices start at off. The first one to turn on will get (or maybe,) the next one gets, etc…

If, for whatever reason, the friend’s network settings have it at a static IP (say, it always wants to be,) then every time another PC/device tries to log in the router gets confused because it could be assigning the same IP to two devices.

I tried upgrading the router yesterday and that might have solved the problem. We haven’t had a chance to test it with all the computers at once though. Fingers crossed.