Who's Connected to My Wi-Fi: Check and Block

A sudden drop in internet speed or strange activity on your router's indicators are often the first warning signs that your network isn't as secure as you thought. Unauthorized access Wi-Fi access isn't just about traffic theft, it's also a potential threat to your personal data stored on computers and smartphones within the local network. Many users aren't even aware that neighbors or hackers could be using their connection for years.

Modern routers have powerful monitoring tools that allow you to see everyone who is "on the air" in real time. Administrative panel Devices is a control panel that displays the IP addresses, MAC addresses, and names of connected devices. Ignoring this information can lead to bandwidth congestion, which is especially noticeable when watching 4K video or playing online games.

In this article, we'll take a detailed look at algorithms for identifying uninvited guests and methods for blocking them. Access control — a basic skill every home Wi-Fi owner needs. You'll learn to distinguish your devices from others and apply security settings that minimize the risk of hacking.

Signs of an unauthorized connection to the network

The first sign of trouble is often unstable internet performance. If you notice that pages are taking longer than usual to load, or that video streams are constantly buffering even when there's no active download on your devices, you should be wary. Traffic — the resource is limited, and when it is shared by several extra users, productivity drops for everyone.

Pay attention to the router's indicators. Light WLAN or Wi-Fi The light may flash wildly, even when all your devices are in sleep mode or turned off. This indicates that someone else is constantly transmitting data packets using your access point.

⚠️ Attention: Some antivirus programs and background operating system services can create a network load. Before you panic, make sure your computers aren't automatically updating games or backing up to the cloud.

Another sign is the inability to access the router settings. If the address 192.168.0.1 or 192.168.1.1 stopped opening, perhaps the attacker changed the administrator password in an attempt to gain a foothold in the system. In such a situation reset settings may become the only way out.

For accurate diagnostics, it's useful to use specialized snails. They scan the airwaves and display a list of all visible devices, even those attempting to conceal their presence.

📊 Have you noticed any strange behavior from your router?

Yes, it blinks for no reason.

The Internet has become very slow.

There was nothing suspicious.

The router reboots itself

Checking connected devices via a router

The most reliable way to find out who's connected to your Wi-Fi is to look inside your router. To do this, open a browser and enter the gateway IP address. Most often, this is 192.168.0.1, 192.168.1.1 or 192.168.31.1 (For Xiaomi). The exact address is usually indicated on a sticker on the bottom of the device.

After entering your login and password (by default, often admin/admin) Go to the section responsible for wireless networking. It may have different names in different firmware versions: Wireless, Wi-Fi Settings, Client List or "Client List." This displays a table of all active connections.

☑️ Checking the client list

Enter the router's IP address in the browserLog in to the control panelFind the Wireless or Status sectionExplore the list of connected devicesCompare MAC addresses with your gadgets

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In the list, you'll see MAC addresses—unique identifiers for network interfaces. Compare them with the addresses of your phones, laptops, and TVs. You can find your smartphone's MAC address in the settings: About the phone → General information or Settings → Wi-Fi → InformationAny unfamiliar device is a cause for concern.

Modern routers such as Keenetic, TP-Link or Asus, often have mobile apps. These make verification even easier: you see a graphical network diagram, with each device labeled or identified by an icon. This allows you to instantly identify an intruder by model name, for example, iPhone-13 or Windows-PC.

Using network scanning programs

If access to your router is blocked or you want to conduct a more in-depth analysis, third-party network scanning programs can help. They operate at the ARP protocol level and display all devices communicating on your local network, even if they are hidden in the router interface.

One of the most popular and effective utilities is Wireless Network Watcher from NirSoft. This portable program, requiring no installation, instantly lists all connected clients. It displays the IP address, MAC address, network adapter manufacturer, and device name.

For users of smartphones based on Android an app would be a great solution FingIt doesn't just display a list, but can also identify the device type (camera, printer, phone) and even check for security vulnerabilities. Scanning takes only a few seconds.

Why do scanners show more devices than the router?

Scanners see not only active Wi-Fi clients, but also devices connected via cable (LAN), as well as gadgets that have recently been online and left traces in the ARP table, even if they are currently dormant.

It's important to understand that such programs only work when your computer or phone is connected to the same network you're checking. Remotely, via mobile internet, you won't be able to see your home network devices without special router configuration.

Table: Comparison of detection methods

Each method has its advantages and disadvantages. The router's web interface provides full control over blocking, but isn't always convenient for quick browsing. Third-party apps are more convenient but require installation.

Verification method	Data accuracy	Complexity	Blocking capability
Router web interface	High (official data)	Average	Yes, complete
Router mobile application	High	Low	Yes, in one click
Network scanners (Fing, WN Watcher)	Average (depends on ARP cache)	Low	No (diagnostics only)
Command line (arp -a)	Low (cache only)	High	No

As the table shows, for regular monitoring, it's best to use the router's built-in tools or its official app. Scanners, however, are good for one-time, in-depth diagnostics when you need to understand what's going on in the air.

The most accurate picture is provided by a combination of methods: comparing data from the router's web interface and scanning results via Fing or similar.

How to block an unknown device

Once you detect an intruder, you must immediately block their access. The most effective way is to use MAC filtering Or use the Blacklist function in your router settings. Find the offending client in the list and click the block button or add its MAC address to the blacklist.

If the lock function for a specific device is unavailable, the only radical solution is to change the Wi-Fi network password. Go to the section Wireless Security or Wireless network securityCreate a complex password that contains mixed-case letters and numbers and save the settings.

After changing your password or enabling filtering, reboot your router. This will terminate all current connections. Any attacker attempting to connect again will be denied access because their credentials are no longer allowed or the old password is no longer valid.

Remember that after blocking or changing the password, your internet speed should be restored. If this doesn't happen, the problem may not be Wi-Fi theft, but rather a faulty equipment or provider line.

Preventive measures and increased protection

To prevent a repeat of this situation, you need to ensure reliable security for your network perimeter. First and foremost, stop using encryption. WEP or WPAThese standards are long outdated and can be hacked in a few minutes even by an inexperienced hacker using automated scripts.

Use only modern encryption protocols WPA2-PSK or, if your hardware supports it, WPA3This will make intercepting and decrypting the password virtually impossible for the average user. It's also critical to change the factory password for accessing the router settings.

⚠️ Attention: Factory administrator passwords (admin/admin) are the same for thousands of devices of the same model. Attackers can access your router's settings even without knowing the Wi-Fi password unless you've changed the control panel access rights.

An additional security measure is to disable the function WPSThis technology allows you to connect to a network without entering a password (for example, using a PIN code or a button), but it contains vulnerabilities that make it easy to guess the PIN code and discover the network password.

Update your router firmware regularly. Manufacturers constantly release updates to patch security holes. You can check for a new version in the section System Tools → Firmware Upgrade.

Frequently Asked Questions (FAQ)

Can my neighbor see my files if he is connected to Wi-Fi?

Wi-Fi access alone doesn't automatically grant access to files on your computer. However, if network discovery and folder sharing are enabled in your operating system (e.g., Windows), an attacker could theoretically attempt to access public resources. Therefore, on public networks or if you suspect a hack, always select the "Public" network profile, which hides your PC from others.

Why didn't the speed increase after changing the password?

The problem may not be traffic theft. Low speeds can be caused by bandwidth congestion from neighboring routers, faulty cable connections from your ISP, outdated hardware, or software errors in the router itself. Try rebooting your device or contacting your ISP's technical support.

Is it dangerous to give your Wi-Fi password to guests?

Sharing your main home network password isn't recommended. It's better to set up a guest network. This feature is available in almost all modern routers. A guest network is isolated from your main local network, so guests won't be able to access your printers, NAS storage, or computers, even if they want to.

How can I find out who is connected if I forgot my router password?

If you don't remember the password for your router's control panel, you'll need to reset it. There's a small hole on the router's casing that you can press with a paperclip for 10-15 seconds. This will reset the router to factory settings, and the password will be the one on the sticker. Afterward, you'll need to set up your internet connection again.