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If I Share Wi-Fi With My Neighbor, Can They See My Network Traffic?

Plus what else might be exposed.

Neighbor Sharing Wi-Fi
(Image: canva.com)
Sharing Wi-Fi with your neighbor might seem like a friendly thing to do, but be aware you are potentially putting your own computers at risk.
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Question: I have a home network with three computers (two desktops connected with ethernet cables to a 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.)?

Let me make one important correction to what you’ve described:

If you give someone access to your Wi-Fi, you have given them access to your network.

They’re on it.

What they can see depends on a number of things. Chances are they can not see your traffic, but even so — to be blunt, I hope you trust them.

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TL;DR:

Perils of sharing Wi-Fi

A Wi-Fi connection is a direct connection to your local network. While Wi-Fi encryption is important, it does not protect you from malicious behavior by connected machines. While there’s a tiny chance network traffic could be exposed, of greater concern is that anything shared on your local network would be accessible to anyone connected. Of greatest concern is the possibility that the connected machine could, inadvertently or otherwise, spread malware.

A Wi-Fi connection

It’s important to realize that a wireless connection — regardless of how your hardware is set up — is a connection to your network. It’s the equivalent to running a cable between the connected machine and your router.

A very common scenario looks like this:

Simple Wireless Router setup

That’s a simple setup where multiple computers are connected to the internet via a single device: a wireless router. Some computers are wired, and some are connected via Wi-Fi.

It’s important to realize that this is exactly equivalent to this:

Simple network setup using a wireless access point

A wireless router just puts the wireless access point in the same box as the router itself, but in either case, it’s nothing more than a connection to your local network.

And of course, machines on your local network should all be able to “see” each other.

Wi-Fi encryption

It’s good that your wireless access point is using encryption, but it’s important to realize what it does and does not do.

It does not protect you from your neighbor.

By giving your neighbor the key, the encryption does not affect your security with them at all. It’s as if they were connected directly to your network — because they are. It’s almost the same thing as having given them a wired connection to your router.

The Wi-Fi password (or encryption key) protects only the connection between the computer and the Wi-Fi access point. The key is required to be able to connect wirelessly. This prevents others — people to whom you have not given the password — from accessing your network, and protects data sent wirelessly from being viewed by others as well.

But that’s it.

What’s the risk?

There are three basic risks:1

  • If you have computers sharing files or a printer, your neighbor may be able to access those files or print to your printer.
  • There’s a tiny risk your neighbor may be able to “see” some or all of your network traffic. I call it tiny because routers typically do not route traffic to computers not involved in the conversation.
  • If your neighbor’s computer becomes infected with malware, that malware may propagate to your machines.

To be honest, it’s the last one that scares me the most.

The first two are all about your neighbor’s intention, which in most cases is probably honest and above board and is at least something you can attempt to judge. The latter, however, involves your neighbor’s ability to keep their own system free of malicious software. That’s a risk I’d be reluctant to take even with the best of intentions.

To address your banking concern: as long as your bank is using https, then I don’t see an issue. This encrypts the connection between your computer and the bank, so even if your neighbor was able to see your network traffic, they would not be able to decode your banking conversation.2

Protecting Yourself

So, short of denying your neighbor access to your network, what can you do?

At a minimum, turn on the Windows or other software firewall on every machine you have on your network. The good news is this is the default behavior in recent versions of Windows.

A more secure approach is to use a second router:

Using two routers

The important characteristic here is that there is a router between your local network and the point at which your neighbor connects.

As I often say, a router acts as a firewall, and as such it has a “trusted” side — your local network — and an “untrusted” side — normally the internet — that it’s protecting you from. This setup draws that trusted/untrusted line between you and your neighbor.

Yet another approach is to get a wireless router specifically designed for this application. In recent years, wireless routers have come to market providing two separate wireless connections, one of which — typically called a ‘guest’ network — is isolated from your local network. While the intent is to provide access to the occasional guest in your home, this connection could also be the one you share with your neighbor.

One Possible Legality

Finally, there’s one more thing I want you to look into before you agree to share your internet connection with anyone.

I want you to check the terms of service with your ISP.

It’s very possible — likely, even — that they explicitly prohibit this type of sharing (you’re taking away a potential customer, after all).

While it’s unlikely that they would detect the connection was being shared with a neighbor, if they did, you could be penalized in some fashion.

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Footnotes & References

1: Note that on a password-protected WiFi hotspot, being able to access the hotspot does not imply that you can also sniff the traffic of other computers connected to the same hotspot. Even though the password to connect is shared among all users, in WPA and WPA2 the actual encryption key used for each connection is different.

2: However, there are no absolutes. If your neighbor had malicious intent or had been infected with a specific form of malware, he could potentially access your router and compromise even https connections.

127 comments on “If I Share Wi-Fi With My Neighbor, Can They See My Network Traffic?”

  1. Actually, his router is most likely a routing switch, which would allow his neighbor to use ARP Poisoning to view traffic to and from other computers in his home network. You’re right, though, that traffic to and from his bank is probably encrypted (via https) so ARP poisoning still won’t enable his neighbor to actually read any of that particular data once it’s captured. Unencrypted traffic, however, would be vulnerable.

    Reply
  2. That isn’t completely true. I agree that the obvious is the sharing of files and printers.

    But, depending on how techie the neighbor is, he could very likely see anything happening on the network. I manage our office network and have my computer set up to sniff all packets that carry thru to the internet. The neighbor could very well do that too.

    But then again, if he is able to do that then he is probably able to break a WEP anyway so you might as well befriend him and seek his loyalty.

    Reply
  3. 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.

    Reply
  4. 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

    Reply
  5. 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?

    Reply
  6. 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.

    Reply
  7. 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.

    Reply
    • My neighbor gave me his Wi-Fi so I could have Netflix on my TV and he also put it on my phone so does that mean he hasaccessibility to all of my information phone etc.Can he hack my phone?

      Reply
      • As long as you are on his network, he can intercept any information that travels across that network. If you have file sharing enabled on your devices (computer, phone, tablet, etc.) he may have access to those. Using a VPN would protect your network traffic against sniffing, but Netflix blocks many VPNs to block people from watching show which aren’t available in the users’ countries, so you might have to turn the VPN off to watch Netflix if this happens.
        How Do I Protect Myself from My ISP?
        In this case your neighbor is your ISP as they are providing you with internet service.

        Reply
  8. —–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—–

    Reply
  9. 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

    Reply
  10. 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
    Reply
  11. 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.

    Reply
    • Wow. This is an old comment, but I feel I need to address the ignorance/disinformation here. One, even if they’re on your network, they cannot simply add a password, they need to have your router admin password, and even if you did not set one up, routers still have a standard admin password that varies from router to router, so they wouldn’t immediately be able to change it. Two, even if they managed to change your admin password, or router network password, it’s not a big deal because you can reset it by directly connecting to the router through an ethernet cable connected to your computer. And three, even if you regularly change your password, andeven if you haven’t noticed any changes or any weirdness, that isn’t a guarantee that you haven’t been hacked, you would most likely not notice it.

      Reply
  12. 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?

    Reply
  13. So as long as the neighbours are not using hacker tools, it sounds like the data going through that shared network may be safe from them. But what if they don’t have an anti-virus, or bother upkeeping it, and pick up viruses and trojans while surfing the net? Does having computers logging into your secured wifi but NOT your domain pose a security risk if they contain malware? THis may be an aspect that the person asking the initial question may not have considered; it’s also something I’m wondering about as I work for a school and we are currently letting students – with who-knows-what kind of security on their laptops – access our secured encrypted wifi. They cannot access our domain with their laptops as it requires an admin logon and is protected by various layers of policies. But can the wifi access alone be an open door to the system from an unprotected laptop?

    Any time you allow an untrusted computer to connect to your network – be it via Wifi, encrypted or not, or by a hardwired connection – you are putting every computer on your network at risk. Malware can indeed propagate to other machines on your network.

    Leo
    14-Mar-2010

    Reply
  14. I agree with Leo. Any untrusted machines on your network can potentially spread viruses to computers on your domain even if they don’t specifically connect to the domain.
    I write software for detection of unknown computers on networks, and generally my customers are much more worried about viruses from home laptops then from someone cracking the WEP or WPA encryption and specically targeting their business.
    It’s just a much more likely scenario.

    I believe that many years ago this is exactly what brought a portion of Microsoft internally to it’s knees: a virus that someone had brought in from home on their personal or portable computer. Fortunately I was on sabbatical at the time.

    Leo
    31-Mar-2010

    Reply
  15. This answers part of the question; BUT, HOW to see what the neighbor has been accessing, at this point?

    In general, you cannot. You should assume that they can see anything without leaving traces.

    Leo
    15-Oct-2010

    Reply
  16. Thanks Leo, My questions have been answered. I’ve learned not to share my wifi. My neighbor came to me and ask if I could share the password to share the internet. They just moved into the neighborhood I do not know them.
    I google you and signed up for your newsletters. I feel better about saying “No”!!!
    Again Thanks.

    Reply
  17. Thank you for this information. I had a new neighbor asking for connectivity to my network over wifi. They just moved in and I was very unsure about it. This post helped take my decision in 5 minutes and do it so politely. Thank u!!

    Reply
  18. I have moved into a home and I have a Macbook and I watch porn. We share the same router. He is my landlord, can he track all the sites I use. They are adult sites and nothing illegal. I have removed the history and cookies, does this help

    Clearing history and cookies only helps if he has access to your computer. As the article you just commented on points out, he can see all your network traffic unless it’s encrypted.

    Leo
    20-Aug-2011
    Reply
  19. In reference to the Wi-Fi ‘hackers’

    What about restricting access to only allow approved MAC addresses, hidden network ID, and having an encrypted password?

    I saw no one saying to hide the network ID, as well as the mac address.

    Here is another question that an answer may prove useful.

    Is there a way to allow a neighbor to use our internet, but actually on a separate “guest” network? Therefore, if his computer gets infected, mine can’t?

    Thanks!
    Scott

    Reply
  20. i watch porn on my ipod through wifi and i still live with my parents can they see my history on the pc even though i delete it on my ipod history every time after use???

    There are several approaches that your parents could use to notice that you’ve been visiting porn sites, even if you delete your iPod history.

    Leo
    06-Dec-2011
    Reply
  21. I have a setting on my router to set the number of connections allowed at one time as well as a tracking log that emails me a log file of network traffic and sites that anyone using my network/internet visit. Highly recommend this for anyone with kids/teenagers. I can also set a time limit and the times that the connection can be used, password protected. The downside though is that if the modem/router is manually reset to factory settings, all settings are deleted along with the security passwords. So, protect access to your modem/router. I agree with Leo as to the legality of sharing the WIFI with a neighbor. That could be breaking your contract agreement with the ISP. As for the porn being streamed over the internet, the ISP should be policing that and limiting access. Those who want to access porn over the net should have to register with their ISP for a fee and permit like pay per view channels. As for kids, parents can set most modems/routers to block sites and activities. The modem firewall has many settings that can be password protected. Another caution on sharing your WIFI with anyone, they can upload/download anything using your ISP connection and it shows up on your record log of use and sites visited. You are held responsible for any/all activity on your ISP connection. Nothing is 100% secure on the net. Personal privacy doesn’t exist, your information can be accessed at any time without your knowledge of it being done until the authorities knock on your door. Last word; don’t share your WiFi with anyone outside of your household/family. If you set up a Guest Acct for a visitor, delete it when they are done with it. Any files/media/printers that are shared on your home network are accessible to anyone with access to that network.

    Reply
  22. I live in a 20 unit apt building. There are at least three other wireless/WiFi modem/routers in the building or nearby. I have checked them out when they show up on the wireless connections. One out of three is an unsecured connection. Leaving it open for anyone to connect and access. At times when I have found an open unsecured connection and am able to, I send an alert to the site that their connection is not protected. Many ppl don’t know how to set up a secure WiFi connection. Especially when leaving their connection open for any Guest to connect via WiFi. If I don’t need my WiFi on or will not be using it for a while, I shut it off via the modem/router wireless settings. If you don’t use your WiFi often, shut it off. It only takes the click of a button to turn it off and on. And it keeps others from connecting without your knowledge.

    Reply
  23. You might as well give your neighbor a key to your house to use while you’re on vacation. If you have bank account numbers, passwords, etc, sharing your network (wired or wireless) will give them, (and possibly their children’s friends who visit) access. Do you really want that? don’t be so naive, lock your system up as tight as you’d lock your doors in your house.

    Reply
  24. This is what happened to me a few years ago.

    I gave a friend my router password and told him not to tell anybody. Next thing you know his other friends are using my system too. I just don’t do that any more. Unless my guest is from out of town.

    Reply
  25. Just a short story, if you allow neighbors to use your internet. I own a small IT business, and allowed a neighbor I have know for some time to use my internet. One day, three very big guys that didn’t smile showed up. To make a long story shorter, the neighbor had sent a threatening email to his ex-wife, they tracked it to my IP, and all my computers spent several weeks at the police station undergoing forensics. Luckily, I got them back with my data. Just a warning, if you loan out your intenet.

    Reply
  26. If you’re going to do it and you trust your neighbor not to do anything illegal, then you should at least use two routers. When I travel and stay with people I bring my router with me along with an extra Ethernet cable. You simply plug your cable into the yellow port on your router and the other end into one of the ports on their router that are usually used to make a wired connection. This gives you your own network. If somebody wants to use your connection then they should have to pay for the extra router, they can be bought very cheap these days.

    Reply
  27. So I am confused. If I let my neighbor use my WI-FI, he can see my activities on the net. But did you say that I could NOT see his activities? Surely I misunderstood.

    No, I will not let my neighbor have that privilege, but nosy people want to know.

    I don’t think I said that. When you give your neighbor access to your WiFi in a sense you’re acting as his ISP, and can indeed see everything he does that isn’t encrypted.

    Leo
    06-Jul-2012
    Reply
  28. One more thing you can do that will help with security. If you don’t need to share files between computers, when you first establish a connection to the network with Windows 7. It will ask what type of connection you are on, Home, business or public, Chose the one that says you’re on a public. It’s the one they recommend for coffee shops and other public connections. This way the network sharing doesn’t work. Just don’t select home even though you’re at home. Unless you need to share files between computers on your network which I don’t normally do.

    Reply
  29. Two things occur to me. One is that if you specify a unique workgroup name for your machine(s) and make sure your neighbor/other user has a different workgroup name for their machine(s), you shouldn’t have problems with any party accidentally viewing each other’s traffic. If your neighbor suddenly renames their workgroup to be the same as yours, that’s a deal breaker.

    The second thing relates to locking down your network – which you should be doing anyway, whether you allow other users onto your system or not.

    Restrict the number of IP addresses that are allocated to no more than can be legitimately connected. Specify named systems that are allocated to specific IP addresses that you assign. Get the MAC addresses of every system that’s going to be using your router and restrict access to those only.

    Switch off broadcasting so that it’s harder (but not impossible) for war drivers to see your router. And create as long and unintelligible a password to your router as you possibly can (there are websites that will assess proposed passwords for you and tell you if they’re any good). This is one you CAN write down somewhere in case you forget it.

    Install a decent firewall. ZoneAlarm do a free version if cost is your main concern, and it checks incoming and outgoing traffic. True, it can be a pain sometimes but being stopped and asked if it’s OK for an application to access the Internet is far better than knowing nothing at all about what’s going on behind the scenes on your machine. Insist that your neighbor also installs similar protection.

    Hard core hackers would have no trouble getting past most if not all of these precautionary measures – but why would they want to? It’s like worrying that a drug cartel might “borrow” your bicycle to shift ten tons of marijuana. T’ain’t gonna happen.

    Reply
  30. There are several more downsides to sharing your Internet. Just two: If your neighbour spams people, you may find that you send email, and it gets rejected as coming from a spam site. Or perhaps he sets up a kiddie porn server, and then you’re going to have a very large legal bill.

    Reply
  31. A lot of new routers have the ability to setup ‘Guest’ access. Guest networks are separate from your own wifi network, with a different SSID and a different Password. Although your shares and machines will be protected from your guests, you will still be responsible for any misuse of your internet by your guests.

    Reply
  32. One thing that hits me that you seem to have overlooked. What if that neighbour uses it to do masses of download (like movies) and pushes u over your limit with the ISP and ends up costing you for the extra download (or at a minimum slowing your connection speed because ISP moves it to slower rate because you have exceeded the limit)

    Reply
  33. You had also best hope your neighbor isn’t doing anything egregious/illegal or the men in blue will probably cuff first and ask later…

    Reply
  34. It’s funny, but I don’t think Leo stressed the trust thing enough. I have actually been learning how to watch the traffic of others on a network, and even how to steal the passwords they put in. It’s so easy that there are tools that do it for you.

    That being said, if you trust your neighbors then it’s not an issue. Also putting yourself behind a second router will stop that from happening as well. I suggest you make absolutely sure that you trust them.

    Reply
  35. I would not give a neighbor my WiFi password under any circumstances.

    Further, I would further secure each computer by…

    — On Windows, make sure that the network you connect to is treated as “Public” unless it is a network that you trust completely and have taken pains to secure. That means that you trust every device that connects to that network. Then you can treat is as “Home or Office” and turn on settings like “network discovery.” Once you have chosen “Public” as the kind of network, open the “Advanced Sharing Settings” and ensure that the “Public” profile settings are tightened up. Turn off Network Discovery and review all the other security settings.

    — On Mac, look through the settings and review the “Sharing” settings. Don’t forget Network and Sharing settings, and the sharing settings in iTunes, iChat, and iPhoto.

    — On your WiFi router, check the “wireless isolation” (or “AP isolation”) setting. You might want to turn this on, at least for your guest networks. Don’t forget both the 5G and 2.4G networks. You might actually have 4 networks! (Why have more than two?)

    Reply
  36. I think you just taught me something about my own router. I use a cheap Linksys E1200, and the Cisco connect lets me set up a 2nd access for guests. My guests are happy with it, but now I think it is the special 2nd connection you recommend. I just took that to be standard.

    Reply
  37. If you travel and use the wireless connection in a rented condo …. can the other guests and/or condo owners also see all your stuff?

    It depends on how it’s configured, but you should assume that the answer is “yes”.

    Leo
    02-Apr-2013
    Reply
  38. My Belkin router has a setting for a DMZ where I can put a server to run games on with people on the internet. Could I put the neighbors machine into the DMZ port and be safe?

    I don’t believe so, no. Your machines won’t be protected from them. (And on top of that, THEY won’t be protected from the internet.)

    Leo
    03-Apr-2013
    Reply
  39. I suggest that in the third diagram-

    “Router 1” should be labelled “Original Router”

    “Router 2” should be labelled “Added Router”

    That then allows the owner to make the changes, without the neighbour being aware.

    Also potentially “Added Router” could have its own similarly-secured WiFi

    Reply
  40. Guess who gets prosecuted if the neighbor views kiddie porn or does file sharing? He should stop sharing the connection with the neighbor, right away. A guest of the neighbor can do these crimes, too. The neighbor may be more than willing to share the key with others, it is not his connection, after all.

    Reply
  41. Ignoring what has already been said, and I concur with steven, what about password protecting the shares on the wired computers?

    While that may protect those shares, it does nothing to prevent other network traffic from being intercepted.

    Leo
    05-Apr-2013

    Reply
  42. You should really think about what could happen if your neighbor downloads child porn. The download would be traced to you! Police at your door at 4:00 AM, search warrant in hand, sifting through all your files looking for that child porn. Threats of long imprisonment! Best not to share that connection!

    Reply
  43. A friend in another business in my building gave me a unique password for his wifi system, just so I can use it when I need to when I bring my laptop there. Is this as bad as the situation in your article?

    Reply
  44. I implemented the two router solution shown by Leo for a small non-profit school so that parents could surn while waiting for their children’s lessons. The parents like it.

    Implementation was an incredible hassle, basically trial and error to configure both routers. Can someone give a lucid explanation of the way and better the theory bheind putting two routers onto different “subnets” so they don’t interfere with each other? Changing the subnet masks was not the way to do it.

    Reply
  45. Never give your password for router to a friend or anyone even if you trust them you have no idea what he or her dose on the internet. Like one comment said child porn how do you no he or her dont look at it. best to not do this i would re set it if i was you.

    Reply
  46. John O’Meara:

    This is a little long-winded, but I have done this for both my home and my office to separate all wireless clients from my

    wired network.

    A router’s job is to separate networks, your private home network from the public internet. Let’s say for example you have a

    wired router for yourself, and a wireless router that you want to have available for guests. But you want the wireless

    network to be separate from your wired network.

    The simplest way to do this:
    First thing is to hard-wire your computer to the wireless router ONLY. You will be making changes to the wireless network

    setup and do not want to be disconnected midway through. Don’t worry about internet access as all you are doing is

    reconfiguring the wireless router for right now.

    What you are trying to accomplish is making the wireless router have a different LAN IP address & IP range than your wired

    router.

    Example: If the wired router’s local LAN IP is 192.168.1.1 (What you type in a browser to configure the router) you can

    change the wireless router’s local LAN IP to 192.168.2.1, (Or 10.0.0.1, whatever) and leave DHCP enabled on the wireless

    router so it can hand out IP addresses to wireless client’s.

    The wireless client’s IP addresses will be part of the 192.168.2.x network and not the 192.168.1.x network. You can leave the

    wireless router’s subnet mask as 255.255.255.0 or if the wireless router changes it, that is OK too.

    The only thing left is to set the wireless router’s WAN IP. It probably will get the IP from the wired router’s DHCP, but I

    like to statically assign it using a higher IP outside of the wired IP range (Ex 192.168.1.254). The WAN IP of the WIRELESS

    router has to match the LAN IP range of the WIRED router. This is where a lot of confusion occurs.

    When you plug the wired router’s LAN port into the wireless router’s WAN (internet) port you are separating the 2 networks.

    Nothing on the wireless side can see or connect to anything on the wired side & vise-versa.

    The only problem doing it this way, since they are TOTALLY separate, is administering the wireless router through your web

    browser. You can do it through a wireless client, but if you want to do it from your wired desktop you need to enable port

    forwarding on your wired router to the remote management port of the wireless router, typically 8080.

    Reply
  47. I must confess that I have NOT read every reply as I feel my problem is slightly different. I lent my laptop to a neighbour, he used it Online using his router. Now I find that intermittently when I power up my connection defaults to HIS router rather than mine. I have no interest in his router traffic, or anything else on his computer. How do I stop my laptop ‘finding’ his router?

    Reply
  48. After reading these posts I have decided NOT to ask my neighbor if if i can share their internet connection. I am looking for a new job and I cannot afford an additional $50/mth. added to my already obscene cable bill. I am positive my neighbors aren’t hackers or pedophiles. I guess it was a bad idea. Now I will worry about all wifi hotspots. Thanks alot.

    Reply
  49. Hi i been reading alot of the comments but mine is a little different i have the xfinity router and my neighbor keeps trying to hack her way on the wifi for her computer without my permission i don’t want her on there have changed my name and password but she still tries to get on all day like a job sometimes she does sometimes she doesn’t. I use my laptop and Netflix and have to change all the passwords again Please help and tell me how to turn off my wifi until i need it for my iphone ..Thanks

    Reply
  50. Hi, I have a wireless router that I have installed in my neighbors house wired to their wireless router. I have my set up as an access point. I know for a fact that the router that mine is connected to is one that has a snooper thing on it… Is my surfing visible to them?

    Reply
  51. Perhaps you might find this to be of interest…

    A man received the following text from his neighbour:
    “I am so sorry Bob. I’ve been riddled with guilt and I have to confess. I
    have been getting onto your wife, day and night, when you’re not around. In
    fact, more than you. I’m not getting any at home, but that’s no excuse.

    I can no longer live with the guilt and I hope you will accept my sincerest
    apology with my promise that it won’t happen again”.

    Bob, anguished and betrayed, went into his bedroom, grabbed his gun, and
    without a word, shot his wife.

    A few moments later, a second text came in:

    Damn Autospelling…I meant “WiFi”, not “Wife”.

    Reply
  52. Hello, I have a wifi modem provided by telus. It’s an ZyXel brand. Someone was using my ipaddress so I strengthened my password on my wifi network. I saw a neighbour in the hall afterwards holding what looked like a wifi modem. I was too shy to ask what he was doing. But I suspect he might have been up to no good.
    Anyway, I connected my iMac to the wifi modem’s LAN with ethernet cable. I don’t know how to turn off the wifi on the modem or even if my computer is at risk if I’m using wired connection through a wifi modem?

    I’m concerned about identity theft mostly.

    Reply
  53. It is a shame that the router model wasn’t described in the question. Most modern mid to high range routers can use guest networks today. These networks requires that the person deliberately hack into the rest of the network to see any activity at all.

    Personally I use an Asus-n66u. In my opinion the most effecient, handy router used in private networking. I need the speed it provides because I host net-parties where I have my ISP bump my net to 300/300mbps.

    The n66u can divide single ports from the rest and assign permissions from for each MAC address. It also has guest network as I mentioned earlier with a separate password.

    Reply
  54. hai leo..how do u do..
    i want to acess to wifi network with my friend who is staying in third floor of my apartment and i am in 1 st floor..my friend is ready for sharing his wifi to me..but we both tried two three modems but i am not able get signal strength in my room..he is having an ADSL connection..can you please find a solution for us..the distance between the floor is not more than 15 mtrs..i am waiting for your reply..thank you

    Reply
  55. I have weird porno sites on my memory that I did not go to. I always suspected my neighbor was stealing my wifi. Is it possible his activities show up on my computer?

    Reply
  56. hi Leo,
    I read this entire article and am confused because the article was written years ago. Reading later posts about a guest wifi password, I’d like to know if this is a newer, safer method of providing a neighbor with a few days of guest wifi than what you initially described?

    With guest access is malware still an issue?

    My husband and I are on Mac’s, I believe they are on PCs. Any good etiquette tips?

    Please advise. Thank you.

    Reply
    • Using Macs would add a layer of security against PCs on the network as PC viruses wouldn’t normally spread from PCs to Macs. Pretty much everything else in the article still applies.
      There is one danger that’s hard to prevent. I let a friend’s daughter use my WiFi and she downloaded a movie for which I received a bill from a lawyer for $1300. She paid the bill, but the lesson remains. Oh, and she was using a Mac :-)

      Reply
  57. I have a wireless modem for phone only never secured. Got a new tv with wifi i now see my unsecure modem. Is anything I play on my dvd player secure nobody else can see it?

    Reply
  58. Leo, pardon if I am asking something already totally addressed, I’ve read the above.
    My house is very large and solidly built, and our wifi within the home is fairly weak,
    so much so, we don’t get signal in the lower level even though there are open atriums
    and open walls for signal to travel. ON TOP OF THAT, we bought the abandoned house
    next door and want to use it as an office for ourselves. HOW DO WE use our ONE cable account
    to have wifi signal in both homes, which are only 30 feet apart. I want to boost signal enough so that our residence and our workspace next door don’t require two duplicative cable (isp) accounts.

    Reply
  59. i am studying class9 .i don”t have much knowledge about internet. i took help of my neighbor to gain internet access somehow he got my password. i do not want him to use up my password. please suggest me.sir

    Reply
    • You should change your router password. You can check the documentation which came with your router or look for instructions on the router manufacturer’s website for instructions for your router.

      Reply
  60. I live in the 3rd World and have WiFi internet. A 16 yo neighbor has asked for my password to access the internet on his smartphone. He is a good kid and I am certain he has no alterior motives. Tonight, I put the password into his phone and asked that he not share it. Since he never saw it, can he share ?

    Reply
  61. I Live With Family And Privacy Is A Huge Issue They Have Xfinity Comcast Wifi With A Personal Security Are They Capable Of Knowing Which People I Communicate With On Facebook Or Even Read The Messages That I Send Or Open The Ones That Have Been Already Read Before After Or All Together Also I Have The Newest MacBook It Has An Option On Safari Called New Private Window Does That Help At All And If So How Much Also Are They Capable Of Using My Stored Passwords And Act As My Computer And Have The Freedom To Act As My Computer On The Sites I Visited And Read And Go Through Things I Have Not Open But Have Been Opened Before?

    Facebook Can They Act As My Computer With Freedom To Do As They Want Once Opened Under Xfinity Comcast Wifi That Has Personal Security Also Own New MacBook it Has An Option For New Private Window How Safe Am I? Also If I Was To Clear My History is It Still Saved Under Theres?

    Reply
  62. This is such B.S
    Lets be honest. Maybe 1 out of 5000000 people can get into someones wifi and control their computer and do the stuff like this hacker says is possible. I used open wifi before and you can’t see anything on other peoples computers if you are using example a neighbors. People like Verizon and internet companies put that fear out there so everyone will get a provider and people want to pretend to be cool go along with it like they can really do it. You can’t. It’s just wifi signal.
    It’s nothing. Yes you can use internet but you can’t see anything from the persons who is the owner of the router/modem.
    If that was the case places like Starbucks and McDonalds would not offer free wifi. Think about it

    Reply
  63. If I use a neighbours WIFI LAN connection having given me his password, could he see my internet traffic, emails, passwords, banking etc.

    Reply
  64. If your neighbor is downloading movies, or worse, illegal images and videos, the feds will come knocking at YOUR DOOR!

    Reply
  65. Interesting thread. Scenario: If someone has an account and password for Broadband with unlimited WIFI and says it is OK to use their WIFI. They give you their user name and password. Would the owner of the account be able to see that other person’s data at all? Multiple people using one account logging in with the same user name and password, with the account holder’s permission? I have read different answers on different sites. WIFI = very confusing!

    Reply
    • It all depends on how it’s set up. It is actually very common in a household with more than one person to share a wifi connection, all using the same password. Each person logs into the wifi from their own device. Of course the ISP can see what devices are connecting, and where they are browsing. Whether they provide this information to the consumer will depend on how they choose to set up their service. One example is my Verizon account. We have three phones in the family and I can go online and see how much data each phone has used. I can see what phone numbers they have called on my final bill. However, they don’t provide me a way to see all the websites each device has browsed to.

      So that’s why you are getting conflicting answers… it depends.

      Reply
  66. I have a friend the just bought a vehicle it was nice to have the mode to be able to communicate on there car, the person that sold to her, for got to delete, omg phone, numbers and personal information they have share, by paring there phone to there vehicle omg………….I have pull the owners manual and delete all ………….for there protection……….amen

    Reply
  67. I’m still not completely sure about something. I am the owner of the WiFi and only I have the password to the modem. I share the internet with my neighbor, only trough wireless connection. Is it possible for him to see what I’m doing? And if so, how hard would it be for him to see what I’m doing on the internet?

    Reply
  68. Hello everybody! A lot of good advise on here for sure, however just like every other thread I’ve read anywhere, all the questions seem to be close if not ALMOST exactly the setup question I have at my apartment but yet not exactly what I was looking for. So here’s what I’m working with…Firstly I’ll give you a rundown of my setup and then ask my questions about it.

    I live across the street from a local bar, they have a password protected Wi-Fi Guest option for their customers, all you have to do is ask the bartender or whoever else works there and they will gladly give it to ya, so I did just that. I could also get the guest signal across the street in my apartment but just barely. I had an extra Wi-Fi extender laying around so I decided to boost the signal over here at my pad. Things seemed to work pretty good, however not perfect like when it was my own high-speed smart home. Mostly because my extender isn’t the very best, top shelf extender plus that original distance jump across the street is actually more like 60 yards with some obstacles, so I’m lucky to get the signal at all especially in the city, but I do so although surfing around on my laptop was more than doable I didn’t have MY network I used to with all of my connected devices and it just didn’t seem like I should have to change all of my devises login credentials. Plus it would be almost overwhelming to change every smart home device I have, including my tablets, phones, desktop, laptops, Alexa, all 8 of my D-Link wireless outlets that work with Alexa to turn things on and off, my security camera system with each camera being Wi-Fi, smart TV, Kodi box, Wireless Alarm system, etc. I’m sure there’s more but you get the idea..(I’m single [by choice], and I’m a bit of a Techy.). There’s a lot of stuff to go through. So I still had my respectful and fairly new Nighthawk R7000 Wi-Fi router so I just ran an Ethernet cord from my Wi-Fi extender to my Nighthawk R7000 and boooyaaa! I had my whole home network back with all of my pointless, lazy smart devices working. (Although Alexa is pretty slow most of the time now, I’m guessing because of the distance plus the processing speed of 2 units plus the one you’re using to view the data) My Nighthawk of course has it’s own password in which I use for my network and for guests too. (That alone should be a kind of firewall of preventing anyone of seeing my files, right? Plus I could even change the password coming off of the Wi-Fi extender too so that it’s not the same as the bar already knows, but if my Nighthawk is enough of a firewall then I won’t worry about it…

    Now my main question would be- Can an employee whom knows a little about computers and works in the office at the bar see the files on my computers? Because I have it setup to where I can watch my drone videos and all videos, pics, music, whatever, to be easily accessible by both of my smart TV’s, along with my phones and tablets as well. Because when I first starting getting into all of the smart stuff, or even Wi-Fi in general, I had a friend over and he had his laptop with him to show me something and he quickly brought to my attention that when he went to his “Network” in his file manager that not only did his computer show up, but so did mine, and he was able to view all of my videos, docs, pics, etc. The Network and sharing options in Windows 7, 8, 10, may not be to confusing to some, but it is to me, and that’s when things were simple and just using my own network and internet, let alone a public bar across the street. So to solve that problem easily was to change my router PW, enable Guest mode, and let him along with other use that from then on because I couldn’t figure out how to share all of my stuff at MY OWN convenience without him or anyone looking seeing it as well.
    This is getting waaay to long. So I’ll just ask my questions and hope for good answers…
    -Can the bar see my vid, pics, docs, etc.?
    -Can the bar see my traffic, history, sites I visit, etc.?
    -What exactly can the bar see from there end?
    -Is this even legal? Even if the bar owner says he didn’t care? What are the consequences if caught and what is the probability of getting caught?
    -Do I need to make any changes that I’m unaware of in either my Windows network and Sharing settings OR in my Netgear Genie settings ORRR in my Extender’s settings???
    Obviously I have a lot of privacy questions as I’m just unaware on how these devises talk to each other, especially going backwards from my computers hard drive to the bar. I’d appreciate any advise if you have any for me!!! Thank you soooo much!!!

    Reply
    • The short answer is that it’s possible they could see things. It really depends on a whole host of issues that are very hardware and configuration specific.

      More importantly: what you’re doing is illegal. And wrong. Unless the bar has actually given you permission to use their internet when you’re not actually at the bar, or while you’re a customer, you are stealing from them.

      Reply
  69. I know this says comments but I have a question & I’m really hoping u can help with this issue. Its my son whom I allowed to use the wifi to have FB. All these things are beginning to “pop up” on his phone & now I realize he’s been visiting suspicious sites. How do I remove the access from his phone now? Hope it’s not too late for our accts. Thx

    Reply
    • If you turn off your Wi-Fi at the router or access point, then yes, you’re turning it off for everyone. If you’re just turning your computer off, then that affects no one else. If you just want them off your Wi-Fi but want to keep the router turned on, then yes, change the password.

      Reply
  70. Hi,

    I read Leo’s reply to, If I Let My Neighbor Share My WiFi, Can They See My Network Traffic, and many of the posts below it. Maybe I’m missing something, but it doesn’t look like Leo, or the above replies, answer the question.

    My landlords let’s me use their Fios wifi. I just enter their password on my phone and laptop. But the landlord indirectly references a few sites I’ve visited. Not as a warning or anything like that. They’re not crazy sites, just stuff like concert dates, diet and workout sites, and media feeds. After I view them, the sites and topics are initiated by my landlord in casual conversations. If my personal traffic is being monitored by them, It’s scary, really disgusting and time to move. I’m super concerned that if they see my traffic, then they can also see my gmail. So this is a great question, I’m hoping someone posts definitive answers to 1) if my landlord can see my traffic when I use their wifi and 2) can they also see my email 3) how can I protect my laptop, phone from this? Thanks!!

    Reply
  71. Please help me figure out how my neighbors are watching and hearing my every move. They say they can’t be caught. He works as a technical maintenance engineer and his wife works at a communications company. Who do I need to figure out how they are doing same.

    Reply
  72. Hi Team Leo – I am curious about your advice on sharing a broadband connection with a couple of neighbors via line-of-sight transmission. We are located in a rural area where broadband is hard to come by, but there are some neighborhoods where fiber is available. I own two properties (one with 1 Gbps fiber) and another that is only served by satellite (9 Mbps on its best days).

    If I use a line-of-sight wireless broadcast network from my fiber connection at my first property, relayed across two other users’ homes along the way, I can reach my second property via line-of-sight transmission from the last relay point, which should theoretically result in up to 200 Mbps at my second property where neither fiber nor cable is available (only unreliable and slow satellite internet).

    The positives are:
    1) I would be getting 20x speed at my second property than what is otherwise available via satellite,
    2) there would be no additional monthly costs, just the initial investment in the equipment
    3) Since I have dedicated “wholesale” fiber at my first property I can legally share the broadband with other users without running afoul of breaching any service agreements with my ISP (I can essentially be an ISP for others), which will allow the users providing the relay sites to benefit from access to a faster connection as my fiber connection is transmitted through their homes along the way to my second property.

    My concerns are as follows:
    1) How do I protect my network on the both ends? Will a piece of hardware such as a Dell Sonicwall on either end provide sufficient security?
    2) Should I be concerned about the risk of potential illegal activity of the other users with the relays along the way using the broadband provided by me (such as spamming, child porn, etc, that has been mentioned by other commenters previously)?

    Any other concerns I should be watching out for?

    It seems with proper firewall protection I should be okay on the first concern, but the second seems hard to fully protect against.

    Reply
    • 1. This article and the Related Posts explain how to protect your connection from being snooped on.
      2. That one is more complicated. Not being lawyers, we can’t give legal advice, but that is very concerning. Proving your innocence can sometimes be expensive. I know someone who was bankrupt by legal costs because some doctors in his rehab clinic were doing illegal business. He won the case but lost his and his parents’ homes in the process.

      Reply
  73. I didn’t see WPA2 encription mentioned. I have a printer compatibility problem with WPA2 but would like to use it because it is much more secure. I am currently stuck with WPA/WPA2.

    Reply
  74. …And that “trusted” neighbor gives that Wi-Fi password to the neighbor on the other side of the person who has the wireless access point (or in the next apartment). Or that “trusted” neighbor gives the Wi-Fi password to his visiting relatives who do nefarious things on the internet. NO THANK YOU!

    Reply
  75. On a similar note, what about sharing wifi with roommates? Particularly with one who is knowledgeable on “hacking”. Is there any ways to fully protect myself from this situation? The wifi is paid for by the roommate and not the landlord. Any advice/tips is appreciated.
    Thanks

    Reply

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