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:

Article C2395 - July 26, 2005

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

Your Name:
Your Email:


Why Subscribe?

Recent Comments
12 Comments

With regards to file sharing with all on the network, you should be able to specify which usernames/computers are able to view shared folders in Windows, right?

If you share a folder containing files by right-clicking and selecting "Sharing and Security...", then check "share this folder", then click on "Permissions", you should be able to add/remove individual user access. Default is everyone.

Not sure if this only works with domain users, as a small home network usually uses a workgroup, unless you're rich/clever/bored/mad and choose to use a Domain Controller for less than 10 PC's.

Also not sure if this is only available to XP Pro users.

Posted by: Andy at July 28, 2005 3:59 AM

Hey pholks

i just got a bran new sony laptop it has a 802.11 b/n wirless card my brother lives 2 doors down and has his wireless network for open access so he lets me connect to it, But hes on holidays for 3 months and the signal strenth is low and i keep gettin disconected is there any type of a wireless attena i could get for it? at a decent price that would improve the singal strenth? thanks alot

JoNNiE D

Posted by: JoNNiE at October 31, 2005 11:19 AM

go the other way can i see who is connected to my wireless access point

Posted by: steve z at May 1, 2006 5:56 PM

i dont have a wireless computer but a router and i have an anti-virus and a privacy guardian, is it possible for local people to see my web surfing?

Posted by: lee at January 27, 2007 6:19 AM

How do you secure it if i pc has xp home with no permissions feature and windows media center on other pc both of which have simple file sharing enabled how do i keep the neighbors from seeing shared folders.

Posted by: jeff at February 25, 2007 3:59 AM

As a hacker I would like to tell you the dangers of wi-fi. Sure it's great. No more running network cables through the walls. Wi-Fi is a goddie zone for hackers reguardless of encryption can be hacked. So no Wi-Fi is secured to really good hackers. They snoop through all your files on no matter what computer. And yes even if you had a hacker on your wi-fi he or she is too apart your network now. They can activate your web cam and watch and hear. It is a new scarry digital age. They can install pro rat which is a spyware program that can be changed by hackers to get pass your firewall or spyware scanner. Now they can monitor your computer from any network on the internet. Right now Im on a wi-fi and it is not my own. I dont have a wi-fi on my actual cable modem. I use a router and network cables because I dont take the risk of any other hacker piggybacking on my network. I suggest through the wi-fi networks out in the trash cause If I was on your network I could even look at pictures you have saved. I could even check you internet history even your cache for that matter. Nothing is safe with wi-fi. your just inviteing hackers to your network. They can be right outside your house launching virus or even sending death threats to the government and you get visited by the cops or fbi depending where your too.

Posted by: kracker at June 3, 2007 5:07 AM

-----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

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...

Please wait. Your comment is being processed ...


Question? Ask Leo!