How to Tell If Someone Is Stealing Your Wi-Fi – Business Insider
There are several ways to detect if someone is stealing your Wi-Fi.
If you suspect someone is stealing your Wi-Fi, you can look for router network activity.
There are third-party mobile apps that can help ferret out unauthorized Wi-Fi users.
Your router’s web-based admin control panel can help you see what devices are using your network.
Visit Business Insider’s Tech Reference library for more stories.
Something is loading.
You’ve no doubt heard the warning for years: It’s critically important to secure your home network with strong Wi-Fi security and a password. Without adequate security, neighbors and other strangers can not only steal your Wi-Fi — a service you no doubt pay for— but the freeloaders might also have access to shared folders and other resources on your network.
How to tell if someone is stealing your Wi-FiIf you are concerned that someone might be stealing your Wi-Fi, there are a few tools at your disposal for finding out. Check your Wi-Fi router’s status lightsThe easiest way to see if someone unauthorized is using your Wi-Fi is to look at your router – but this only works if you can take all your wireless devices offline completely. If you have a lot of devices (like smart home gadgets) using Wi-Fi, don’t bother with this approach and go straight to the next. But if you can count all the devices on your Wi-Fi network on one hand, take them offline — either turn them off or set them to
airplane mode. Then watch the status lights on your Wi-Fi router. With no devices using Wi-Fi, the lights should not be flickering or flashing. If they are, someone else is probably connecting to your network.
Use a Wi-Fi detective appThere are a lot of apps available in the app store for your mobile device that promise to scan your network and provide a list of all the connected devices. You can search the app store for options, but one reliable app is called WiFi Guard, available for both iOS and Android. This app gives you a list of all connected devices, which you can scan to see if there are any devices you don’t recognize.
WiFi Guard is one of many apps that can show you a list of all devices using your network.
Dave Johnson/Business Insider
Many devices will be identified with easily understood names, like your laptop, phone, and some smart home devices. But some may be reported as “unknown device, ” which is relatively unhelpful when trying to determine which are yours and which are interloping.
Use your router’s appIf you have a relatively modern Wi-Fi router, it probably works with a mobile app — in fact, you might have initially configured the router using the app. If that’s the case, you can start the app on your phone and look for a network map, log, or client list. Every router is different and there’s no standardization among router software, so you’ll need to explore. But if you can find this list, it’s essentially an “official” version of the device list from the third-party Wi-Fi detective app. If you have a multiband router, the app will probably even show which radio (such as 2. 4GHz or 5GHz) each device is connected to.
Use your router’s mobile app to look for a list of connected devices.
Log into your admin control panelIf none of those other options are fruitful, your last (and often the most complicated) option is to log into your router’s admin control panel in a web browser. To do this, you’ll need to know:Your admin username: By default, this is almost always “admin, ” though if you practiced good security hygiene, you changed it to something else when you first set up your router. Your admin password: If you have an older router and you never changed the password, this might be hacker bait like “default” or “password. ” Hopefully you’ve changed IP address: Most of the time, your network’s IP address is — enter that address in a web browser and log in if you are offered the opportunity. If that’s not right, you need to find the IP address for your network: In the Start search box, type “ipconfig” and press Enter. Your IP address should be the “Default Gateway. ”
You can find your IP address using the Windows ipconfig tool.
After you’ve logged into your admin control panel, look for a network map, user log, or client list. As we mentioned earlier, every router is different and there’s no standardization among router software, so you’ll need to explore to find it.
How to kick someone off your networkIf you do find an unauthorized device on your home network, there are two simple ways to get rid of them:If you see an unauthorized client in your router’s mobile app or admin control panel, select the entry for that device. You should see the option to block, ban, or eject the device.
You may be able to block devices from your router’s app or admin control panel.
Rather than blocking devices one at a time, you can throw every device off the network at once (including your own devices) by changing the Wi-Fi password. If you don’t already use a password, you should absolutely turn on network security and add a password right now. Even if you already have a password, if someone is using your network and you don’t know how they got access, you should change your password and make it stronger. If your network offers multiple kinds of security, step up to a more secure system, such as moving from WPA or WPA2-TKIP to WPA2-AES. Related coverage from Tech Reference:How to change your Wi-Fi password and secure your internet connectionHow to make a Wi-Fi password to protect your internet, or change your existing passwordHow to enable and use Wi-Fi calling on your Android or iPhone to make calls without cellular serviceHow to change the IP address on an Android phone or tablet using a ‘static’ addressHow to find the IP address of your internet router using a Mac, PC, iPhone, or Android
Dave Johnson is a technology journalist who writes about consumer tech and how the industry is transforming the speculative world of science fiction into modern-day real life. Dave grew up in New Jersey before entering the Air Force to operate satellites, teach space operations, and do space launch planning. He then spent eight years as a content lead on the Windows team at Microsoft. As a photographer, Dave has photographed wolves in their natural environment; he’s also a scuba instructor and co-host of several podcasts. Dave is the author of more than two dozen books and has contributed to many sites and publications including CNET, Forbes, PC World, How To Geek, and Insider.
Receive a selection of our best stories daily based on your reading preferences.
Tech How To
It indicates an expandable section or menu, or sometimes previous / next navigation options.
An icon in the shape of a lightning bolt.
How To Scan Network for IP Addresses Using cmd Tools …
Scanning for IP address lets you have better control over your network. With 1-2 commands, you can quickly map out the devices in your network and the IP addresses that they are using. But to understand how to scan a network, first, you need to understand how are IP addresses assigned.
Follow these four simple steps to scan your network for IP addresses in use:Open a Command Prompt Windows or macOS type ipconfig or on Linux type ifconfig. Press return. Note down the subnet mask, the default gateway, and your own computer’s IPv4 the command arp -a to get a list of all other IP addresses active on your the command ping
DHCP (Assigning IPs Dynamically)
An automated process in networking, called DHCP (Dynamic Host Configuration Protocol), assigns IP dynamic addresses to hosts as soon as they enter the network. In a home or small network, the DHCP server is usually a part of the router. When you come into the network, the router will look for an available IP address in its pool and assign it to you, so that your device can communicate with others without any conflict.
Dynamic allocation of IP addresses is a great advantage for both end-users and network admins. But sometimes you would need to have some control in order to manage and troubleshoot your network more efficiently.
Related post: Find device or IP with MAC
Related Post: Powershell Kill Process Command
What will you learn in this Tutorial
In this tutorial, you will learn the basic networking skills on how to scan a network for IP addresses. We will scan a network with native OS commands, find which addresses were assigned dynamically, which statically, and test their connectivity.
In the end, we will compare some free IPAM tools aka IP address scanning tools that can give you additional information. To improve your IP addressing insights, even more, we will show you some tools that allow you to track IP addresses and even manage them.
Simple IP Scanning
Operating Systems, like Windows and Linux, come with their own native simple networking set of tools. Commands such as “ipconfig”, “arp -a”, or “ping” allow simple scanning and troubleshooting.
The simplest way to get a quick list of IP addresses and their devices connected to your network is with those OS native commands found in the command line. With a list of the assigned IP address and their devices, you can easily find the devices that are causing the most problems.
This command displays all network settings assigned to one or all adapters in the computer. You can find information such as your own IP, subnet, and Gateway. For Linux and MacOS is “ifconfig”.
When you issue the “arp -a”, you’ll get IP-address-to-mac conversion and the allocation type (whether dynamic or static) of all devices in your network.
It helps determine connectivity between two hosts and find the IP address of a hostname.
Related Post: Best IP & Port Scanners
Reading The Output
Finding your own network adapter configuration
In the following screenshot, you’ll see the output from the ipconfig command. On a Windows, the ipconfig command can be entered through the Command line.
Go to Run > type cmd > type ipconfig
This Windows computer has 5 network adapters, but the last one (Wireless LAN adapter Wi-Fi) is the only one connected to a network. The rest are disconnected.
In this network, the router (or Default Gateway) is playing the role of the DHCP server. It is assigning the IP address dynamically and giving access to the Internet.
You are reading two of the most important IP addresses for your device; Your own device’s IP (IPv4 and IPv6) and your Gateway. The Subnet Mask is also very important, it shows that you are on the same subnet as the gateway.
Now you know your subnet, which in this case is 192. 168. 1. 0/24 (using the CIDR range). Now you need to find the rest of the IP address in your network.
Scanning your Network
The job of the ARP protocol is to map IPs to MAC addresses. It provides a method for hosts on a LAN to communicate without knowing any address and create a cache of information. When a new computer enters the LAN, it receives an IP and updates its ARP cache with the Gateway information. This ARP cache can be found using the “arp-a” command.
Use the command line to enter the “arp -a” command.
This computer has been connected for some time into the LAN, so its ARP cache is very precise and complete. The first IP address shown in the display is the Gateway (the same we found through the ipconfig command).
The output shows the IP, the MAC addresses, and their assignation type. The addresses displayed here were dynamically assigned by the DHCP server in the LAN. All of these IPs are devices connected to the LAN (192. 0/24). The other static addresses are reserved for Multicasting.
With the MAC information, you can know the vendor. Try searching for vendor prefixes or use an automatic online tool such as MACvendors.
Finally, with some information, you can test connectivity. In the following test, we tried an extended ping with “ping -t” to the gateway. With this, you can learn some simple insights about delay and latency.
From the list generated by the ARP command, you could ping all the live hosts. Or you can go beyond and ping the entire subnet to find hosts not found by the ARP (but that would be too much manual work…). Later, we’ll discuss how to automatically ping entire subnets at once.
Enhancing IP Scanning
Although having a list of devices and their allocated IP address will give you good insights, the information will not be enough when your network scales. Manual IP scanning in multiple subnets and BYOD (Bring-Your-Own-Device) scenarios is nearly impossible. As the network scales, problems will scale too.
Larger networks demand more results, flexibility, and easy-to-read set of commands.
An IP Address Scanner tool helps you with larger demands. These tools are able to map the entire local network, finds live hosts, and to provide the results of the “arp-a” in a clearer format. Other IP Scanners do not depend on ARP but they operate using repeated ping tests. A Ping Sweep tool lets you ping entire subnets and find live hosts just with one button.
Some other IP Scanners go the extra mile and give more information such as Port number, DNS, DHCP, etc. All of this data is also presented in the most visual and easy-to-read format. They also allow users to save all results and present them in detailed reports.
Advanced IP Scanners
Here is our list of the seven best tools for discovering IP addresses on a network.
SolarWinds Port Scanner (FREE TOOL) A free IP address scanner that will search for all addresses within a given range and identify which are in use and then examine which ports on each device are active. This tool uses multi-threading for high-speed searches. Installs on Windows Server.
ManageEngine OpUtils (FREE TRIAL) A suite of network address monitoring tools that covers IP addresses, MAC addresses, and port numbers with a cut-down free version also available. Installs on Windows Server and Linux.
Angry IP Scanner A free network scanner that identifies all connected devices and lists their IP addresses plus connection response speeds. Available for Windows, macOS, Linux.
SolarWinds Ping Sweep (FREE TRIAL) Part of the Engineer’s Toolset, this tool searches the network for all active IP addresses, reporting on the response time and showing hostnames from the local DNS server. Installs on Windows Server.
MyLAN Viewer A network scanner that identifies all connected devices and lists their IP addresses and MAC addresses. Runs on Windows.
SolarWinds IP Address Tracker (FREE TOOL) A free version of the SolarWinds IP Address Manager. This tool is able to discover all devices connected to a network and give details of IP address usage. Runs on Windows Server.
SolarWinds IP Address Scanner (FREE TRIAL) This is part of the SolarWinds IP Address Manager. Use this as a standalone utility to identify all addresses in use or as part of the IPAM for wider IP address management functions. Runs on Windows Server.
The best IP Address discovery tools
1. SolarWinds Port Scanner
The SolarWinds Port Scanner tool is a great all around tool for scanning port DNS Addresses and IP’s within the range that you specify, along with advanced abilities and capabilities that make it our #1 Choice on the list.
Some great features of this tool include some of the following features:
Ability to create a list of Open/Closed/Filtered Ports of IP addresses specified in your range
Scan Range along with specified TCP & UDP ports for identifying possible vulnerabilities
Multi-threaded Scanning for Faster Scans!
Ability to Launch and Run from either GUI or Command-line
Choose a Custom DNS Server to use for Scanning
Ability to Save Customized Configurations for Scanning
Manage & Track Device and User Activity
Edit & View IANA Port name definitions
Export to CSV File for Bulk Editing and More!
ManageEngine OpUtils combines an IP address manager, a switch port mapper for MAC address discovery, and a port scanner to identify open TCP and UDP ports on all devices. This combination delivers all address-related functions that you will need in order to fully manage your network.
The IP address manager is, in itself, a suite of utilities. This group of services includes an IP address scanner. This will discover all of the devices connected to your network and list the IP addresses allocated to them. The IPAM is able to produce IP address reconciliation reports that will enable you to update your native DHCP server in case it fails to notice expired address leases.
The IP address tracker service in the bundle can produce a hierarchical view of your network, enabling you to identify subnets and the allocation of addresses to each. DHCP management tools in the pack let you manage subnet address pools. The switch port mapper identifies each device by MAC address and switch port number. The port scanner in OpUtils lets you see which TCP and UDP ports on each device are open.
OpUtils is available for Windows Server and for Linux.
OpUtils is available in a Free version, which includes a port scanner and Ping utilities. Contact the ManageEngine sales team for a quote on the paid version.
The paid version of OpUtils can be downloaded as a 30-day free trial.
3. Angry IP Scanner
Angry IP Scanner is one of the most popular scanners on the web, with over 29 million downloads. It is open-source, free, and available for Windows, MacOS, and Linux. It can let you scan your local network or the Internet-facing IP addresses.
This tool is not only capable of scanning IP addresses but also ports. When you define an IP address range, you can also specify a number of the port, and see if a device in your network is using a specific service (defined by the port). Angry IP Scanner also lets you save all the scan results into multiple formats, such as TXT, XML, CVS, etc.
When you scan, you’ll know what hosts are alive, their response time, hostname, MAC address, etc. If you want even more information, you can extend results by developing Java plugins.
Open Source and 100% free.
Get Angry IP from its official site.
4. SolarWinds Ping Sweep
Ping Sweep from SolarWinds helps you find free IPs and identify which ones are unavailable. It is classified as a networking discovery tool from the SolarWinds Engineer’s Toolset. A comprehensive network software, that includes over 60 handy tools. Ping Sweep from SolarWinds is included in the Engineer’s Toolset and is dedicated for ping testing. For the MAC address, port scans, SNMP scans, etc, there are more dedicated tools in the Engineer’s Toolset.
Just as when you ping from the command line, this tool shows the DNS name for each IP and response time. It can also let you export results in different formats such as CSV, TXT, XLS, and to an HTML page.
SolarWinds Engineer’s Toolset gives you a 14-day Free Trial and it includes over 60 must-have tools.
Get a fully functional Engineer’s Toolset for 14 days by registering to SolarWinds official site.
IP Address Tracker Tools
Having a map of IP addresses, MAC addresses, used ports, etc, is great for networking inventorying and may help with some troubleshooting cases. But a list can not control and display real-time results.
An IP address Tracker is a good upgrade to our set of tools and commands described so far. It does allow scanning multiple subnets and displaying results, but it also allows you to keep track of one or more IP addresses.
An IP Address Tracker will notice when an IP address is released. This can be either because the device lost connectivity or it changed IP address. It will help you minimize IP addressing conflicts (when two devices are trying to take the same IP) and reduce DNS errors.
5. MyLAN Viewer
MyLAN Viewer is a NetBIOS and IP address scanner for Windows systems. Just like the IP Scanners shown above, this tool will scan a network and show devices in an easy-to-read format.
But MyLANViewer goes beyond, and not only shows computer name, IP, and MAC, but also NIC, OS version, logged users, shared folders, and much more.
This tool is able to track specific IP addresses and show notifications when their state change. With it, you can also keep track of network security by showing port information and detecting rogue DHCP servers. MyLAN Viewer tracks all devices in the subnet including hidden, and displays alerts when new devices enter the network, and others go.
This tool can also display the following metrics as well:
Display Whois data.
Manage “Remote Shutdown and Wake On LAN (WOL)”.
Monitor wireless networks.
Free, but only available for Windows systems.
Get MyLAN Viewer from its official site.
Related Post: Best Wake On LAN Tools
6. SolarWinds IP Address Tracker
SolarWinds IP Address Tracker is a standalone software and completely free. In addition to creating inventories of all devices, this tool allows you to scan, track, and manage IP address, including their event logs, all in a single place. SolarWinds IP Tracker is the free version and feature-limited of the much coveted IP Address Manager.
But the IP Tracker does an amazing job to provide a centralized view of the entire IP addressing scheme. It lets you monitor 256 (one subnet) IP addresses for free. Additionally, this tool allows basic management functionalities with tools such as, Ping, Telnet, Traceroute. The best of all is that, with SolarWinds IP Address Tracker you can detect IP address conflicts created by misconfigured DHCP servers.
SolarWinds IP Tracker is only supported by Windows systems.
Register with SolarWinds to download the software for free.
Download 100$ Free!
IP Address Management (IPAM)
Basic IP Address Scanning should be enough to manage small networks. But when networks scale they depend on multiple subnets and detailed management requirements. Although SolarWinds IP Tracker is able to find IP address conflicts, it is not able to control them.
Sometimes large-scale networks have standalone DHCP and DNS Servers in order to assign addresses to multiple subnets. But IP conflicts occur and it is really challenging to manage them manually. An IP Address Management or “IPAM” is a piece of software able to actively control DHCP and DNS. It also gives you the ability to manage multiple subnets.
7. SolarWinds IP Address Scanner
Among SolarWinds powerful tools, the IP Address Manager does everything a large-scale enterprise needs to manage its addresses properly. It automates many processes to make IP Address management easier. From automated IP address tracking, quick static IP reservations, to multi-vendor DHCP and DNS support.
SolarWinds IPAM comes with an integrated IP address management, DHCP, and DNS tools to administer your entire network.
One of the most commonly used tools from this bundle is the IP Address Scanner. This tool allows you to create automated IP address scans to maintain an updated inventory of all IP address blocks in the network. This is achieved by sending regular ICMP and SNMP polls. The automatic scans use ICMP polls to gather status of the IP address and hostname information. It also uses SNMP to find information on MAC addresses and other vendor information. SolarWinds IP Address Scanner supports both IPv4 and IPv6 address management.
SolarWinds IPAM also provides detailed reports of your IP address in real-time.
Download the Free Trial for 30 Days!
Get a fully functional SolarWinds IPAM on a 30-day trial.
Download Free Trial!
IP address scanning FAQs
How do I find a network name from an IP address?
To get the network name of a host from an IP address you need to query the DNS server. Open a Command Prompt window and enter nslookup
How do I identify an unknown device on my network?
To see all of the devices connected to your network, type arp -a in a Command Prompt window. This will show you the allocated IP addresses and the MAC addresses of all connected devices. To get the hostname of each IP address you see in the list, use nslookup
How can I tell what device is at an IP address?
To get deeper information on devices connected to your network rather than just an IP address or MAC address, use a network monitor that scans for details with SNMP – the SolarWinds Network Performance Monitor is one example.
How to See Who’s On Your Wi-Fi | PCMag
(Image: Getty)Is your internet moving a little slower than usual? Are you seeing hints of devices you don’t recognize in File Explorer, or when you cast media to your TV? If you suspect a neighbor is stealing your Wi-Fi, here’s how to check (and boot them off). “So someone’s watching Netflix on my internet, ” you may say. “What’s the big deal? ” Even if you have a little bandwidth to spare, you probably don’t want other people on your network, especially if it’s unsecured. If someone has access to your network, they have access to all the computers on that network, and that’s dangerous. They could access files you’re unknowingly sharing, they could infect you with malware, and in certain situations they could even steal your passwords and other personal information. As a result, you should take care to make sure each device connected to your network is one you trust. Thankfully, there are free tools that will help you see everyone on your Wi-Fi right Who’s On Your Network
Windows users can download a free, portable program called Wireless Network Watcher (scroll down to the Zip download link below “Feedback” to get it), which will provide a list of every device currently connected to your network, so you can identify the ones that belong to use Wireless Network Watcher, just launch the program, and it will immediately begin scanning your network. This will take a minute or two—you’ll know it’s working if the bottom-left corner reads “Scanning… ” Once it’s done, that message will disappear, and you’ll be presented with a full list of connected devices.
The resulting list may look a little cryptic, especially if you aren’t super tech-savvy, but don’t worry. You can ignore the IP address and MAC address listings for now. If you’re using Wireless Network Watcher, just focus on the Device Name and Network Adapter Company example, I see an item named “Dulce” in Wireless Network Watcher, which is the name of my wife’s MacBook. I see another with no name, but with “Philips Lighting BV” as the network adapter manufacturer, it’s probably the hub for my Philips Hue lights. You can double-click on a device to add “User Text” that helps you identify each device and narrow down all the items in this users don’t have as many great options—LanScan is a decent pick, though it costs $6 for the full functionality. Most other apps are either expensive, or have caveats that make them less than ideal. If you’re on a Mac, your router’s settings page may have the info you need. Or, if you have an iPhone, you can give Fing a nsult Your Router Settings
If you’re lucky, you’ll be able to recognize all the items on that list, but there may be a few that don’t have enough information. After going through my list, for example, I was left with a couple devices that listed no name and no manufacturer. However, I was able to get a little more information from my router’s web can open your router’s management page by typing its IP address in your browser’s address bar. Once there, look for an option that sounds like “Attached Devices” or “Client List. ” This will present you with a similar list as Wireless Network Watcher, but the information may be slightly different. After cross-referencing the unknown devices between the two, I found one of them was listed as “AzureWave Technology, Inc” in my router’s interface, but not Wireless Network Watcher. A little Googling revealed that this was my Rachio sprinkler system, so I was able to mark that down and move on.
If you see any other unlabeled devices in the list, check around your house for any internet-connected gadgets you might have missed. I realized that my Amazon Echo wasn’t listed, so after checking the Alexa app on my phone, I was able to match its MAC address to one of the unlabeled items in Wireless Network all goes well, you should be able to identify every device on your network. If there are any left over, and you’ve combed your house looking for other internet-connected devices and found nothing, there’s a chance someone nearby may be using your Up Your Network Security
Even if you discover that a neighbor is stealing your Wi-Fi, you don’t need to hunt them down and start a fuss—you can just kick them off with a change in router security. Head back to your router’s web interface and find the option to change your password (usually under the “Wireless” section somewhere). If you don’t have a password, you absolutely need to start using one, and it needs to be strong. Without a password, your personal information is up for grabs to any amateur hacker that drives by. Choose WPA2 for the password type, since it’s far more difficult to crack than the now-outdated WPS is turned on, you should turn it off, since this feature makes it easier for people to crack your Wi-Fi password. If you want to let guests on your Wi-Fi without giving them access to your devices and information, you can always enable your router’s guest network, or simply share the password you already had a password—maybe it was weak and easy for your neighbors to guess—changing it to something new should be sufficient to kick them off. Of course, you’ll also have to re-authenticate all of your devices, but you should be able to rest a little easier knowing that all the devices on your network belong to you.
Like What You’re Reading?
Sign up for Tips & Tricks newsletter for expert advice to get the most out of your technology.
Frequently Asked Questions about how can i tell if someone is on my network
How can I see all devices on my network?
To see all of the devices connected to your network, type arp -a in a Command Prompt window. This will show you the allocated IP addresses and the MAC addresses of all connected devices.Jul 22, 2021
How can I check who’s using my Wi-Fi?
You can open your router’s management page by typing its IP address in your browser’s address bar. Once there, look for an option that sounds like “Attached Devices” or “Client List.” This will present you with a similar list as Wireless Network Watcher, but the information may be slightly different.