A situation where the wireless network Wi-Fi It distributes traffic without any problems, but the wired connection is silent, confusing many users. It would seem that a physical connection should be more reliable and stable, but in reality, the opposite is often true. The root of the problem can lie in anything from a simple damaged cable to software conflicts in the operating system.
Most often, the culprit is the PC's network adapter itself or incorrect router settings. Local Area Network (LAN) Requires correct port configuration, while the wireless module operates autonomously. Ignoring this fact leads to lengthy and useless reboots of the equipment.
In this article, we'll examine the main causes of the problem and offer a step-by-step solution. You'll learn how to distinguish a software failure from a physical malfunction and quickly restore network access.
Primary diagnostics and visual examination
Before delving into the settings, make sure the physical connection is intact. Often, simply reconnecting the connector solves the problem. RJ-45 or replacing the patch cord. Carefully inspect the cable for kinks, pet bites, or damaged insulation.
Pay attention to the LED indicators. The LEDs on your computer's network card and the corresponding router port should be lit or blinking. Link indication This usually indicates physical contact, even if the internet isn't working. If the lights don't come on, there's no electrical connection.
⚠️ Caution: If the port LEDs are flashing rapidly or are an unusual color (for example, orange instead of green), this may indicate a short circuit in the cable or a speed mismatch.
Try using a different cable that's known to be in good condition. Even a high-quality cable can have a hidden defect in the wire. It's also worth checking that the connector is firmly seated in the socket—a loose port is often the cause of contact loss.
Problems with network adapter drivers
If everything is physically intact, but the internet still doesn't work, it's likely that the operating system isn't interacting correctly with the network card. Drivers are software translators that explain Windows, how to manage hardware. They can disappear after a system update or installing new software.
Check the device status in the Task Manager. To do this, click Win + R and enter the command devmgmt.msc. Find the "Network adapters" section. If next to the name of your card (for example, Realtek PCIe GBE Family Controller) there is a yellow triangle, which means the device is not working properly.
The solution lies in updating or reinstalling the software. Try selecting "Uninstall device," then clicking "Scan for hardware changes" in the action menu. The system will attempt to find and install the default driver again.
In some cases, forcing a change in the duplex speed can help. Go to the adapter properties, select "Configure," and then go to the "Advanced" tab. Find the setting Speed & Duplex and try setting the value 100 Mbps Full Duplex instead of auto-negotiation. This often helps with older routers.
IP address and DNS server settings
A common cause of inaccessibility is an IP address conflict or incorrect DNS settings. If Wi-Fi is working but the cable is not, it's possible the router isn't assigning an address via the protocol. DHCP for a wired interface, or the TCP/IP protocol properties contain a static value that is not suitable for the current network.
You need to check your network connection settings. Go to Control Panel → Network and Internet → Network and Sharing CenterSelect your local area connection, click "Properties" and find Internet Protocol version 4 (TCP/IPv4)Make sure the boxes for automatic address retrieval are checked.
| Parameter | Recommended value | Possible error |
|---|---|---|
| IP address | Receive automatically | Static address from another subnet |
| Subnet mask | 255.255.255.0 | Invalid mask (e.g. 255.0.0.0) |
| Default Gateway | Router address (usually 192.168.0.1) | Lack of gateway |
| DNS | Automatically or 8.8.8.8 | Blocked or broken DNS |
If automatic configuration doesn't help, try manually entering DNS servers. Alternatively, you can use Google's public servers (8.8.8.8) or Yandex (77.88.8.8). This will eliminate problems with domain names.
Router and LAN port malfunctions
It's important to remember that a router is also a mini-computer, which can freeze or generate errors in the operation of individual modules. It happens that the radio module Wi-Fi It functions normally, and the built-in switch for LAN ports is broken.
Try switching the cable to a different port on the back of the router. They are usually numbered 1 through 4. If one port doesn't connect, another may work. It's also a good idea to check the router's web interface settings.
⚠️ Attention: In some router models (for example, Keenetic or MikroTik) ports may be reassigned programmatically or disabled by the administrator. Check if the port is blocked in your security settings.
Resetting your router to factory settings can be a drastic but effective solution. However, keep in mind that you'll have to reconfigure your ISP connection and Wi-Fi password. Use this only if other methods fail.
Software conflicts and antiviruses
Third-party software often interferes with network interfaces. Antivirus software with firewall functionality, traffic optimization programs, or VPN clients may block wired connections, considering them less secure or a priority.
Try temporarily disabling your antivirus and Windows firewall. If the internet works, then the problem lies with your packet filtering rules. You should also check if you have any virtual network adapters installed from programs like Hamachi or Android emulators that can intercept traffic.
The Impact of VPN on Wired Internet
VPN clients often create a virtual adapter that, when enabled, blocks all traffic unless a proper route (split tunneling) is configured. Disable the VPN completely, not just minimize it.
Another option is to reset the network stack via the command line. Launch Terminal as administrator and run the command netsh int ip resetThis will reset your Windows network settings to their original state, removing any accumulated registry errors.
Specifics of the Windows operating system
Sometimes the operating system itself doesn't manage network card power management correctly. Windows may power down the Ethernet port to save power, after which it fails to wake it up correctly. This is a common issue on laptops.
Go to Device Manager, select your network adapter, go to Properties, and open the "Power Management" tab. Uncheck "Allow the computer to turn off this device to save power."
It's also worth checking Windows services. Make sure the service DHCP Client is up and running automatically. Without it, obtaining an IP address from the router is impossible, even if the physical cable is intact.
☑️ Windows diagnostics
When the provider is to blame
External factors also cannot be ruled out. The provider may be performing maintenance on the equipment, affecting only the wired network, or you may run out of funds in your account while Wi-Fi (the local network) continues to work for accessing your account.
Check your balance and service status in your provider's personal account. Sometimes you need to re-register your MAC address if you've changed equipment, although this happens automatically in modern networks. If all else fails, calling technical support is the fastest way to find out about any line issues.
⚠️ Please note: Providers' pricing terms and technical regulations are subject to change. Always check your contract or your internet service provider's official website for current equipment and configuration requirements.
Frequently Asked Questions (FAQ)
Can a virus block only wired internet?
Theoretically, yes, some Trojans can change network settings or block certain interfaces, but in practice, this rarely happens. Most often, the problem lies in the drivers or hardware.
Why is the LAN indicator on but there is no internet?
The indicator only shows the physical presence of a signal (Link), but does not guarantee data transmission. The problem could be a missing IP address, incorrect DNS, or a blocking issue with the router.
Do I need to buy a new cable if the old one stops working?
You don't have to buy it right away. Often, simply tightening the connectors or replacing one is enough. Cables rarely fail on their own; they usually fail as a result of physical damage.
Does cable length affect internet performance?
Yes, the standard length of twisted pair cable without signal amplifiers should not exceed 100 meters. In a home environment, this is rarely a problem, but using excessively long or low-quality extension cables can lead to packet loss.