Look for a device with a yellow exclamation mark named USB 2.0 10/100M Ethernet Adapter or Unknown Device . Right-click the device and select .
If you’ve ever dived into your Device Manager and found a mysterious "Unknown Device" or a hardware ID labeled USB\VID_0FE6&PID_9900 , you’ve likely stumbled upon one of the most common yet confusing budget peripherals on the market. This specific combination identifies the Corechip SR9900 USB 2.0 to Fast Ethernet Adapter
The Corechip SR9900 is a specialized network controller designed to bridge a USB 2.0 interface with a standard 10/100 Mbps Fast Ethernet network. usb vid-0fe6 amp-pid-9900
How to identify the device on your system
: This is often caused by a corrupt driver stack or inadequate power from the USB port. Try plugging the adapter directly into a motherboard port (on the back of a desktop PC) rather than a front panel port or an unpowered USB hub. If the issue persists, completely uninstall the driver from Device Manager, restart the machine, and clean-install an alternate driver version. 3. Limited Speed Capped at 10 Mbps Look for a device with a yellow exclamation mark named USB 2
The 0fe6:9900 USB Ethernet adapter is also well-supported in Linux, but it can sometimes require a bit of manual configuration.
Troubleshooting checklist
Ensure you are not plugging the adapter into a daisy-chained, unpowered USB hub shared with high-draw peripherals like external hard drives. The SR9900 maxes out at . If you are connected to a Gigabit fiber connection, this adapter acts as a bottleneck and will restrict your speeds to Fast Ethernet limits (~11-12 MB/s real-world transfer speeds).
The hardware string identifies the Corechip SR9900 USB 2.0 to Fast Ethernet Adapter , a budget-friendly hardware chip commonly used in compact, low-cost USB-to-LAN dongles. Devices carrying this specific Vendor ID (VID 0FE6) and Product ID (PID 9900) bridge the gap for laptops, tablets, and mini-PCs that lack a dedicated physical RJ45 Ethernet port. Because it is often sold under generic, unbranded plastic casings, users frequently must rely on this exact hardware string to find functional drivers when their operating system fails to configure it automatically. Technical Specifications This specific combination identifies the Corechip SR9900 USB
This output from the dmesg command confirms that the device is found and is being assigned to the eth0 interface.
Download the package matching your system architecture (32-bit or 64-bit). Extract the .zip or .rar folder.