[renpar61]

I am kind of new to wireless connections. I have an iBook G4 with Airport extreme connecting through a Linksys router to share internet DSL connection in my house. On my Airport menu I have a bunch of unknown networks (besides my own) showing up, coming and going. I can connect to some of those. Can you explain? Am I picking up the signal from a neighbor network? Is someone else entering mine?

Thanks for your help.

[jasonsRX7]

How many are a bunch? If you live somewhere like an apartment complex or townhouse (anywhere that several people can live close together) then there's a good chance that you're picking up your neighbors access points.

If you can connect to them, then they're not using any kind of security. Likewise, if you're not using any kind of security, then they can probably connect to you. If you're not using WEP or WPA, you should seriously consider doing so.

[renpar61]

A bunch is 4 or 5, and yes, I live in a townhome. I doubt that I could pick up a signal from 5 different neighbors, though. Can 1 router have more than one named network?
Which is better and easier to use between WPA and WEP, considering I am sharing the network with a laptop PC (Windows ME)?

[jasonsRX7]

There are some wireless access points that support multiple SSID's but they are enterprise class and quite expensive, so it's unlikely that your neighbors are using them.

WPA-PSK (PreShared Key, which Apple refers to as WPA Personal) is far superior to WEP, and should be used if your access point and WinME laptop support it. WinME will require software level support from the manufacturer of the wireless card in that laptop, as the OS doesn't offer it natively (XP does, however).

Thinking about it further, it's possible that a homeowners association could have deployed a WLAN for their residents to subscribe to. In this case, it's likely that they would use access points that support multiple SSID's so they could segment the network using VLANS, thereby creating a private network for each residence, without having to install a separate access point for each one.

[ghporter]

In the townhomes I've been in, you could DEFINITELY pick up 5 or more other wireless networks! Thin walls let plenty of signal through. You wouldn't happen to live near a university campus, would you? Anyway, because of this, you have two different issues to deal with. First you get confused by how many different networks you see, but those other people will also see YOUR network.

Fortunately, your Linksys wireless router supports MAC address filtering. This allows you to select the specific computers you want to be able to connect to your wireless network by their hardware addresses. The manual for your router has very good instructions on how to set this up. If you need help or clarification, ask for it here.

To reduce your confusion, change the name of your wireless network to something memorable and definitely non-default. Linksys stuff defaults to "linksys" for the SSID (the same thing as network name), so change it to something very different, like "Flowers for Algernon," or "Delightful" or something else really non-tech sounding. AND CHANGE THE ADMIN PASSWORD OF YOUR ROUTER RIGHT NOW!!!! It is THAT important in your situation!

Finally, make sure you use the strongest encryption you have available. Windows ME will most likely NOT support WPA. It took a recent update to Windows XP to have that OS support WPA, and Microsoft has pointedly stopped supporting ME (about time, too). That means you're either stuck with WEP or upgrading your PC laptop to XP. A laptop that has ME on it may or may not support XP.

WEP isn't perfect, and can be broken, but it is fairly easy to set up, and is supported by ALL 802.11b and g wireless equipment. And if there are 5 or more wireless networks in your townhome, the odds are that there are at least three that are completely unprotected. Just running WEP will make you too much trouble to mess with for most intruders (it's like locking your door-even a cheap lock gets passed over for an open door).

It would be good if you could track down all your neighbors and tell them that their networks are visible and unprotected, but that's not always a reasonable option. I would try to be a good neighbor-post a notice on a community bulletin board or something like that-so at least I'd done something.

[Scarpa]

Great advice from GHPorter, as usual.

I would add that you can also "hide" the SSID of your wireless router. By default wireless routers will broadcast the SSID of their network to make it easy to connect. This is why you see all your neighbors' networks. If you hide yours they won't see it, but neither will you. You will need to specify the network ID to connect.

If you setup WEP, MAC filtering and hide your SSID you won't need to worry about people getting on your network. The level of knowledge and time necessary to crack that setup is too high, especially considering there are plenty of other ripe targets in the area.

[fizzlemynizzle]

Fortunately, your Linksys wireless router supports MAC address filtering. This allows you to select the specific computers you want to be able to connect to your wireless network by their hardware addresses. The manual for your router has very good instructions on how to set this up. If you need help or clarification, ask for it here.

MAC filtering can be easily circumvented. You need to use WEP or WPA if you want to secure your WLAN.

[Buck_W]

I, too, am brand new to the world of wireless networking. I have a DI 614+ router from D-Link. Is there a way to know (or test) if someone else is entering my network and using my signal without my knowledge?

[John Strung]

If you go into the DLnk Setup utility, you will find a log which will tell you who has connected to your network and when.