Discover who is connected to your network and remove intruders for good

Have you ever noticed slow internet without any apparent reason, or seen an unknown device appearing in your router’s connection list? It’s not paranoia: poorly protected Wi-Fi networks are constant targets for opportunistic neighbors, forgotten devices, and in more serious cases, people intending to monitor your traffic. The good news is that identifying who is on your network and removing unwanted access doesn’t require advanced networking knowledge, just a few minutes and the right tools.

This guide covers everything from basic router panel verification to third-party tools, including how to block specific devices and strengthen security so the problem doesn’t happen again. You’ll need access to your router’s admin panel, which in most cases is accessed through a web browser. If you’ve never done this before, don’t worry: the process is explained step by step.

How to view connected devices through the router panel

The most direct way to find out who is on your network is to access your router’s administration panel. This panel is essentially an internal website, accessible only from within your network, where all device settings are located.

1. Open your browser and type your router’s IP address in the address bar. The most common ones are 192.168.0.1, 192.168.1.1, or 10.0.0.1. If you don’t know yours, on Windows open Command Prompt and type ipconfig; the “Default Gateway” field is your router’s address. On Android or iOS, go to Wi-Fi settings and tap on your connected network name to view details.
2. Log in with username and password. The factory default is usually admin/admin or admin/password and is typically found on the label on the bottom of your router. If someone has changed it and you don’t know the password, you’ll need to do a factory reset by pressing the button on the back of the device for about 10 to 15 seconds.
3. Look for a section called “Connected Devices”, “DHCP Clients”, or “Network Map”. The name varies by manufacturer: on TP-Link Archer routers it’s “DHCP Client List”; on Intelbras routers it appears as “Connected Hosts”; on Multilaser panels it’s usually under “Status”.
4. You’ll see a list with the device name (hostname), the IP address (temporary identifier within the network), and the MAC address (permanent identifier of the network hardware, like an ID card for your Wi-Fi card).

Write down the MAC addresses of everything you recognize: your phone, notebook, smart TV, cameras, smart speakers, and any other device. Anything left over that you can’t identify is a candidate for an intruder or forgotten device.

Tools to scan the network from your computer or phone

The router panel doesn’t always display all devices clearly, especially on simpler models provided by your internet provider. Network scanning tools solve this.

On computer (Windows or Mac): the Wireless Network Watcher application from NirSoft is free and shows all active devices on the network with name, IP, MAC, and network card manufacturer, without installation needed. Another established option is Advanced IP Scanner, also free, with a Portuguese interface.

On mobile: the Fing app (available for Android and iOS) is the gold standard for this function. It scans the network, identifies manufacturers, detects open ports, and even alerts you when a new device connects. The free version works well for home use; the paid version adds continuous monitoring and email alerts.

The logic is simple: any of these apps send small “pings” (verification signals) to all possible IP addresses within your network and wait for responses. Whoever responds appears on the list.

How to identify an unknown device

Seeing a device with a generic name like “android-a3f2bc” or “ESP_4521” doesn’t necessarily mean it’s an intruder. Before panicking, follow this reasoning.

• Check the manufacturer by MAC address. The first six characters of the MAC identify the network card manufacturer. You can search for this prefix in the public IEEE (Institute of Electrical and Electronics Engineers) database or on sites like MACVendors. A MAC starting with “DC:A6:32” belongs to Raspberry Pi Foundation; “B4:E6:2D” is Samsung. This helps a lot in identifying devices without clear names.
• Turn off your devices one by one and see what disappears from the list. Remember to include less obvious devices: secondary routers, Wi-Fi repeaters, smart plugs, connected lamps, and even Wi-Fi printers.
• If any device remains on the list even with everything off, then you really have an intruder or a completely forgotten piece of equipment.

How to block a specific device from your network

Once you’ve identified the intruder, the most effective blocking method is using the MAC address filter or the “blacklist” function present in most modern routers.

1. Access your router’s panel as explained earlier.
2. Locate the list of connected devices and copy the MAC address of the device you want to block.
3. Look for the “Access Control”, “MAC Filter”, or “Blacklist” section. On TP-Link Archer routers, it’s under “Advanced > Access Control”. On Intelbras routers, it’s usually under “Wi-Fi > Access Control”.
4. Add the MAC address to the blacklist and save. The device will lose connection immediately and won’t be able to reconnect, even if it tries.

An important detail: MAC filtering can be bypassed by someone technically experienced using a technique called MAC spoofing (MAC address forgery), where the device mimics the MAC of another. That’s why filtering is a useful barrier, but not the only one you should use.

How to protect your network so this doesn’t happen again

Blocking the intruder solves the symptom. But if your network was accessed by someone unauthorized, something in your setup needs to change.

Change your Wi-Fi password now. Use a password with at least 12 characters, combining uppercase and lowercase letters, numbers, and symbols. Avoid birthdates, pet names, or obvious sequences.

Use the correct security standard. The WPA3 protocol is the most secure available today and is already present in routers released in recent years. If your router only supports WPA2, it’s still acceptable, but avoid WPA and especially WEP, which has been considered insecure since the 2010s. The setting is in “Wireless Security” or “Wireless Security” in your router’s panel.

Change your router admin password. If someone accessed the panel with the default password, they could have made silent changes. Switch to a unique and strong password.

Create a separate network for guests. The “Guest Network” function creates a parallel Wi-Fi isolated from your main network. Visitors, IoT devices (Internet of Things, like cameras and smart lights), and any device you don’t fully trust should be here. That way, even if someone accesses this network, they can’t see your personal computers and phones.

Keep your router’s firmware updated. Manufacturers like TP-Link, Intelbras, and Multilaser release updates that fix security vulnerabilities. In your router’s panel, look for the “Firmware Update” or “System Update” section and check if a newer version is available.

If you use connected devices at home and are concerned about home network security, the same care applies to other gadgets accessing your network, such as cameras used in live streaming. Check the guide on the best webcam for live streaming up to R$ 500 in 2026 to understand which models have support for secure networks and regular firmware updates.

What to do if your router is provided by your ISP

Most Brazilians use the router delivered by their internet provider with their plan. These devices usually have simplified interfaces and, in some cases, the provider maintains remote access to the device for technical support purposes. This isn’t necessarily a problem, but it limits the control you have over your network.

If your provider’s router panel doesn’t offer MAC filtering or adequate access control, you have two alternatives. The first is to contact your provider and request activation of bridge mode, which disables the routing functions of the provider’s equipment and allows you to connect your own router with full control. The second is to place your own router behind the provider’s equipment, configuring it as the main router of your home network.

Intelbras Action and TP-Link Archer routers are widely sold in Brazil, have Anatel approval (mandatory for any radiofrequency equipment sold legally in the country), and offer Portuguese interfaces with the necessary controls. Prices vary greatly depending on the line: entry-level models with Wi-Fi 5 cost between R$ 150 and R$ 250; models with Wi-Fi 6 or Wi-Fi 6E start around R$ 400 and reach much higher values depending on specifications. Confirm current availability and prices at major national retailers.

Frequently asked questions about Wi-Fi monitoring and security

Can my neighbor see what I access on the internet if they’re on my network?

Yes, partially. Someone connected to the same network can use tools to monitor local traffic, which is called a man-in-the-middle attack. Websites using HTTPS encrypt the content, but monitoring can reveal accessed domains. Using a VPN (virtual private network) protects against this type of monitoring.

Does changing my Wi-Fi password disconnect all my home devices?

Yes, all devices using the old password will lose connection and need to reconnect with the new password. This includes smart TVs, speakers, cameras, and any other connected gadget. It’s a tedious process, but necessary when your network has been compromised.

Does MAC filtering really work to block intruders?

It works as an additional barrier, but it’s not foolproof. Someone with technical knowledge can do MAC spoofing and imitate an authorized device’s address. MAC filtering should be used along with a strong password and WPA2 or WPA3 protocol, never as the only line of defense.

How do I know if my router has Anatel approval?

All equipment sold legally in Brazil must have the Anatel seal printed on the packaging or product label. You can also check the approval number on Anatel’s official website to verify authenticity. Imported equipment without this approval has no legal guarantee of operation in Brazilian frequency bands and may experience interference.

Maintain control of your own network

Periodically checking who is connected to your network should become a habit, like checking your credit card statement. Doing this once a month, especially after any visit or new device installation, prevents surprises. The tools exist, are free in most cases, and the process takes less than ten minutes once you know where to look.

If after following all the steps the situation persists, or if you have an environment with more connected devices, like a home office, consider a router with cloud management system or more advanced security features, like those in the TP-Link Deco or Intelbras Mesh lines, which offer detailed network maps and more granular access control directly from your phone app.