How To Tell If Someone Is Using Your Wireless Network

laptop outdoors   How To Tell If Someone Is Using Your Wireless NetworkThere are many reasons you should learn how to check if someone is on your wireless network.  We all know there are security risks associated with it (someone can hack your computer or your internet use stealing important personal information).  There can also be legal implications.  For instance, your neighbor could be doing something illegal and the authorities may accidentally trace the activity back to your equipment.

Although you’re not guilty, proving this can be lengthy, difficult, and frustrating.  Also, does your internet provider like the idea of the neighborhood using your internet service instead of paying for the service themselves?  This could be construed as stealing from the service provider.


In any case, it is good to know how to check if someone is on your wireless network.  In this article I would like to show you how anyone can tell if someone is logging on.

To find people on your wireless network, the process will be different depending on your router’s manufacturer but the basic idea is similar.  Personally, I use a LinkSys because I think their routers are the best.  That is why the screenshots in this article will be from a LinkSys interface.

There are two main methods to tell if someone has been on your wireless network.  You can check the logs to see if someone’s been on there recently or you can check out the DHCP Clients Table to see computers currently connected to your network.  Let’s go through both, shall we?

First Things First, What’s Your IP Address?

The first step is to identify your own IP address (you’d hate tracking and being nervous about your own shadow, right?).  Finding out your own IP address (a.k.a. your LAN IP address) is quite simple.

  • Click the start button
  • Click run (in Vista, just type in the Start Search box)
  • Type cmd then click OK.
  • Type ipconfig when you are given the prompt.  Your IP address will look something like this: “IPv4……………….: [THEN A STRING OF NUMBERS]”  If you need to get a better visual, check out the screenshot below:

412010 110619 AM   How To Tell If Someone Is Using Your Wireless Network

Go ahead and keep that window open because we’ll need more information from it soon.  Now onto the mission before us!

Check The Log To See If Someone’s Been On

The first way to see if someone’s been leeching off your wireless network is to check the logs for unknown IP addresses.

Log into your router by entering its IP address into your browser address bar.  Not sure what the IP address is for the router?  One way is to Google the manufacturer and find what the most likely default IP address is.  Another way is to go back to the ipconfig screen and find it listed as “Default Gateway.”

If you haven’t really set anything up yet, you’ll probably be asked to log in with a username and password.

router login   How To Tell If Someone Is Using Your Wireless Network

Routers are originally shipped with a default username and password.  To find this out you’ll either have to find the documentation that came with the router or use Google to search for the manufacturer and the default login information.

Once in, different routers will have different looks and navigation.  Like I said before, I’m using a LinkSys so that’ll be what I will be describing.  You may have to look for similar settings and words to do what you need to.

Let’s check out the log by going to the “Administration” tab and then the “Log” sub-tab.  Make sure logging is enabled.  Once that is done, the router will log information.

logging   How To Tell If Someone Is Using Your Wireless Network

The information we’re interested in for this article is IP addresses that should not be there.  This obviously means that strangers are logging on to your network.  To find this out, click the “Outgoing Log” button.  The LAN IP column shows the IP address for the computers logging on.  Incidentally you can see the site that was accessed in the “Destination URL/IP” column.

outgoinglogtable   How To Tell If Someone Is Using Your Wireless Network

This should give you a good idea whether or not someone has been accessing the Internet via your wireless network.

Check The DHCP Clients Table To See If Someone’s Currently On

First you must make sure this option is enabled on your router.  Go to the setup tab and look for something similar to “DHCP Server” and make sure “enable” is marked.

dhcp server setting   How To Tell If Someone Is Using Your Wireless Network

Now you can go and check out who’s logged on by going to the “Status” tab and the “Local Network” sub-tab and clicking the “DHCP Clients Table” button.

status localnetwork   How To Tell If Someone Is Using Your Wireless Network

The table that opens offers some useful information about the computers that are connected currently like the Client Host Name (the computers’ names), the IP addresses, and the MAC addresses.

activeIPtable   How To Tell If Someone Is Using Your Wireless Network

So there you have it.  If you want to see who’s been leeching off your wi-fi, that’s how.  Now, what to do about it?  Secure your network better.  Check out these MakeUseOf articles.  They should be able to help some:

Now despite the warnings at the beginning of this article you might not mind others logging on and using your wi-fi.  But now you can at least see what’s going on.

Do you have another way of monitoring your wi-fi network?  Please share your tips in the comments.

The comments were closed because the article is more than 180 days old.

If you have any questions related to what's mentioned in the article or need help with any computer issue, ask it on MakeUseOf Answers—We and our community will be more than happy to help.

25 Comments -

Mike

@Dave – What a worthless comment.

Hey Buddy, send me a link to YOUR recently written, carefully researched, meticulously fact-checked article on “How To Tell If Someone Is Logging On To Your Wireless Network.” Oh wait, you can’t because you haven’t written and published one. You Fail! Go back to surfing for porn and let the intelligent adults go about the business of helping each other out. Kthxbye!

Lance

I wouldn’t say the article is worthless, but it is a bit useless. Instead it should have pointed out facts in order to better help secure the person’s wifi network (aka the actions in order to fix said problem).

James

What is the point of blurring IP addresses that are on your network and behind your firewall? They are not routable and not accessible from the Internet unless someone knows the IP assigned to your network by your ISP and there is a port open/forwarded through the firewall.

timmyjohnboy

Good point. I just like to go blur-crazy!

timmyjohnboy

The article wasn’t meant to rewrite the other MakeUseOf articles I linked to already showing tips on how to secure your WIFI network. The point was merely to show how to see the activity going on.

ankit

kind of pointless since whoever is smart enough to log into your wifi (hacking wep/wpa) is smart enough to spoof his mac address.

Lance

He’s assuming that the person has not encrypted their wifi. (IEW: see my above post)

Srivatsan Venkatesh

So now how do you get the little buggers off your network? Even if it is encrypted already?

Tim

Typically if you are using WPA/WPA2 encryption, you probably won’t have any, um, guests.

Another cool way is to filter MAC addresses and only allow MAC addresses for the specific computers in your home. Log into your router, click “Wireless” then “MAC Filter” subtab.

You can also disable wireless administrating and only allow changes to be made via a network cable.

The best way still is changing the encryption method to some sort of WPA/WPA2

Hope that helps:)

just some guy

I myself like netcut. . .

Joe

One problem I see here; usually I log on to public WiFi with custom settings (ie a custom ip, dns, etc.) although that is usually because they don’t work otherwise (see McDonalds). That won’t show up in the DHCP client table. But to catch the common drive-by WiFi leech, this article is great! One other place to look, if you don’t mind crawling through lots of meaningless data, is the router logs (Administration > Log > View Log > Outgoing Log). It is, however, limited to about 25 lines, so check as soon as you think someone is snooping. Also, the log is almost useless if you like to help seed some linux distros with a box in your basement, since bittorrent kind of goes hog wild connecting to tons of peers and spoiling the logs. But I digress.

Tim Lenahan

Thanks for the tips, Joe. What you say is true.

The log was mentioned in the article but thanks for highlighting as an alternate if the DHCP client table doesn’t show what you need it to.

just some guy

Linksys >> Tomato or DDWRT >> Connected devices. Some routers have a connected devices list by default that includes those connecting with a static IP.

timmyjohnboy

Thanks for the tips, Joe. What you say is true.

The log was mentioned in the article but thanks for highlighting as an alternate if the DHCP client table doesn’t show what you need it to.

moopet

Blurring the IP addresses makes them seem like confidential information.
Blurring one destination IP in blue makes it seem like that’s the bit you should be searching through to find the odd-one-out.
Mentioning that you should be taking into consideration all the IP addresses of known hosts on your network would be handy.
Mentioning that it is only useful if you have been using static addresses, DHCP reservations or your router has been logging its DHCP leases and you’ve got to cross-reference that list would be useful.
Not assuming everyone on your network is running windows, or putting that in the title of the article would be useful.

Giving a brief statement saying how this is only part of the story and can easily be circumvented would be responsible.

Joe

Windows is the dominant platform right now, so I don’t think it was an unreasonable assumption that most users will be running Windows. You can take Linux instructions off the table, since the countless distros would make it impossible to cover them al and 99% of Linux users scoff at even needing directions for a task as menial as checking their IP. But I’ll throw a bone out to all the Macs out there, to check your IP, go to System Preferences > Network > [choose your connection] > IP will be under the Status label.

timmyjohnboy

Like I mentioned before, I go blur-crazy sometimes and blur any kind of identifying numbers, whether they matter or not (the blue was already blue and I blurred the whole lot at once).

In the article I did make mention that “The information we’re interested in for this article is IP addresses that should not be there.” You’re right, I could have made it clearer that one should take note of all addresses that SHOULD be on there so as to find the strangers.

Should I have put “Windows” in the title? Perhaps that’s a good point. Thanks.

filerantings

I have set up passwords for my wireless network and Hardware-Adresss must be added to use my wireless network.

Dave3

I agree with earlier posts, this was virtually useless – the ipconfig screen looks different on different versions of Windows, never mind Mac and Linux, and with DHCP, the first available IP address will be used every time, so unless you log on at the same time as someone else, nothgin will show.

Instead you have to look for foreign MAC addresses, and even that can be spoofed.
This article is bad because it could give someone a false sense of security.

Jo Anne Taylor

This article was exactly what I needed. Thank you for clear directions any old woman could follow and not feel stupid (that is, until I started reading all the comments….).

Anonymous

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mrguitar106

Well Hello to All You Fine People!! I just can’t Stand it Anymore!
The People That Take The Time To Show Others How To Do Things With The Computer~That Is A Very Nice Thing To Do~ And If It Can Help People~In Anyway~ That Is A Very Good Thing~ These Guys Have Put Up Sites For People To Check Out Trying To Save People Money And They Have Put Up Some Cool Stuff!!
You Guys Not To Say Names ( All Of The Above ) Got To Be Kidding Me
You Really Should Only Have Nice Things To Say About makeuseof.com
Or Anyone Trying to Get People To Understanding The Computer Better !
And They Are Doing It For Free
~~~And Doing A Great Service~~~
Understand

ps. I Know All The Guys Above Not Saying Names its Funny To Me How You Guys Know Just Enough To Put Your Self~~~Well Let Me Just Say More GURUs Geee Wizz
Everyone Is A Guru Now!

Anonymous

Dave…why waste your time on here if you dont have the intelligence to understand any of this?

Reginald Hollingsworth IV

I want more discussions on how to tap into wifi signals, not secure them mate!

Jayde

Can I just say, I find this article extremely useful. I’m currently setting up a wireless network and privacy and security are my top priorities. I’ve searched on the net for ways to find out how to check whether someone’s using my connection and see those logged on instantly, but all I found was the log advice.
Thanks for the great tips, Tim. I shall look at the other links now mentioning how to best encrypt the connection. BTW, I used WPA and still had someone trying to hack into my connection at my old address. Never found out whether he got in or not, but with the help of this great article I know how to do it now.