Ask Leo! by Leo A. Notenboom

If I let my neighbor share my WiFi, can they see my network traffic?

Search First! Then browse: Categories | Full Archive | By Date | Newsletter

Home » Networking

I have a home network with 3 computers (two desktops connected with ethernet cables to Linksys router; laptop is wireless). The wireless signal is encrypted and I gave my next door neighbors my network key so they can wirelessly connect just to check email, do banking, etc. They are not on my home network, but can they still see where I am surfing (such as my bank site with passcodes, etc.)?

Well, let me at least make one correction to what you've laid out:

If you've given them access to your wireless access point, they are on your home network. What they can see depends on a couple of things, but to be blunt: I hope you trust them.

It's good that your wireless access point is using WEP encryption. That helps prevent others from accessing your network. In giving your neighbor your WEP key, though, you've given them access to your network. All of it. It's pretty much the same as giving them a cable directly in to your router.

That means that, for example, if you share files or your printer, your neighbor can see them, and possibly access them.

This is the part where you need to trust them. Allowing them on your home network could allow them access to any private files you might have on your computer.

Whether or not they can see your surfing habits depends on your router. If it is indeed a router (and it sounds like it is), chances are their computer cannot see the traffic to and from your computer. A router is typically a smart device that "routes" the data only between the ports that are actually involved in the conversation. However that's an assumption we make of the device, and since the true definition of what a router should or should not do is somewhat vague, it might not always be the case.

Finally, the conversation between you and your bank should be happening over a secure "https" connection, and this is a great example why. A secure connection encrypts the data so that it cannot be seen by anyone other than the two participants in the conversation: you and your bank. This is a computer-to-computer encrypted conversation, so even if your neighbor could monitor the conversation, they wouldn't be able to understand it.

So in your shoes I would actually not be concerned about their ability to monitor your web surfing habits, but instead, I'd be concerned about their ability to see files on the computers in your home network.

Related:

Helpful? Get new articles weekly by email in my FREE newsletter!

Your Name:
Your Email:


Why Subscribe?

Article C2395 - July 26, 2005

Was this article helpful? «Yes» «No»

Recent Comments
13 Comments

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

I'll actually agree to a point. Unsecured WiFi, and WiFi using WEP encryption
is, effectively, open to anyone.

WPA encryption is much better, but it's only as good as the password you
choose. Choose a good - no, *great* - password, and WPA is safe.

Leo
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (MingW32)

iD8DBQFGYvhxCMEe9B/8oqERAuvGAJ9S4dA8zpp8JfRSsBj3CZCs7VvzHgCcCjfF
SQbhDoRRRkPgbmJDlZYTs8A=
=oLmN
-----END PGP SIGNATURE-----

Posted by: Leo A. Notenboom at June 3, 2007 10:21 AM

Well in response to the WPA is safe, I'd have to disagree on that. I'm pretty paranoid when it comes to securtiy especially on WI-FI reason being they arent secure at all being ur using WEP or WPA or WPA-PSK types of encryptions for the network, with the right tools they can be hacked, Someone using ARP poisoning places the hacker between you and the router making all the traffic pass thru his computer then to the router, this way makes his sniffing packets alot easier, even if your on a secured web page like ebay which the page uses https all the packets can be captured and decrypted with a program called (C&A) I'm using the begining of these letters to prevent others from using them but to the know hacker they know what C&A is. Well that is a method a hacker uses when already in a wifi network. But trying to hack a wifi network they first have to see what secured networks are in the area and they use a program called Networ Stumbler, that program detects all wifi signals in the area within range, this program can also detect wifi routers that have their SSID's disabled from broadcast if im correct. Again i'm leaving some stuff out to prevent newbie hackers from getting ideas of hacking wifi,

NetStumbler is commonly used for:

Wardriving
Verifying network configurations
Finding locations with poor coverage in one’s WLAN
Detecting causes of wireless interference
Detecting unauthorized (”rogue”) access points
Aiming directional antennas for long-haul WLAN links

once they see the AP thy want to get into (encrypted WEP WPA etc..) They run a program with the right hardware (WIFI CARD)to sniff out packets, once the packets have been capured from the target they use anogther program to crack the encryption this takes very little time, once thats done the program shows the key thats being used to get on the secured wifi network once having access to the network that you think was secured being wep, wpa etc.. they can being their attacks using easy ways like NetBios attacks or simply snoop around to get your info being credit cards, anything. So these are ways the hackers can get into the secured wifi network, again i have left things out but you get the idea on how this can be done, as far as i know the WPA2 is know to be belived to be uncrackable but i may be wrong, ill be looking into that. But if anyone has any comments feel free to msg me at [Email Address Removed] as I am also very concerned of the lack of security of the Internet these days.

Posted by: Antonio at October 21, 2007 5:03 PM

I have a business and I have WLAN connection. A lot of times I see my neighbor sitting near our building on the rock wall with his computer.... surfing. My guess is that he is using a wireless connection and fishing off my WLAN. I use a wireless and want to continue doing so but would like for him not to be able to connect and receive free internet from my business. What can I do to keep using my business base computer and also my wireless at the same time and not let the neighbor in? Thanks

Enable WPA encryption on your wireless router/access point and stick a password on it.
- Leo
28-Oct-2008

Posted by: Brenda at October 28, 2008 6:10 AM

Worst Case: They enter your router through the network, jus typing http://192.168.x.x etc & they chance the router pwd!!! lo! and u r denied acces to your own router!!!
wifi sucks, but then are there such hacker so easily avaiable??? guess not, a normal web encription, checked in 2-3 days, chance pwd as oftena as possible & its relatively safe...
i mean relatively!!!
NetStubler... well hats off... any wifi is crackable...
tc.

Posted by: Pax at May 25, 2009 7:02 AM

you are all paranoid schizotypal disordered people!
Most of what you say is true in theory but practically most people wont have to worry-because your average neighbor doesn't have any idea how to hack into a network nor has the time. Its like saying not door lock is secure-with the right tools it can be picked-do you go to sleep everything night thinking about that?

Posted by: ramdon at October 18, 2009 3:17 PM

Post a comment on "If I let my neighbor share my WiFi, can they see my network traffic?":






(Email Address will not be published.)

Remember Me?

By popular demand...
my tip jar
Cuppa Joe
Buy Leo a Latte!

(you may use HTML tags for style)

RSS feed Subscribe to the RSS Feed specifically for comments on this article.

Before commenting, please...

  • Read the article at the top of this page. If your comment shows you didn't, it'll be deleted and ignored.

  • Comment only on this article. Use the Google search box at the top of the page if you have a question about something else.

  • Don't include personal information in the comment. No email addresses. No phone numbers. No physical addresses.

  • Don't spam. Excessive links to unrelated sites within a comment or across multiple comments will cause all such comments to be removed.

  • Don't ask me to recover lost passwords or hacked accounts. I can't, and those comments will be deleted.

  • I can't respond to every comment. And I can't vouch for the accuracy of others who do.

Please wait. Your comment is being processed ...


Question? Ask Leo!