# Ubuntu/Debian sudo apt install r8168-dkms # Or use r8169 (built-in) – blacklist if unstable
| Problem | Likely Cause | Fix | |---------|--------------|-----| | No Ethernet after Windows update | Realtek driver replaced by MS inbox driver | Download latest Realtek from motherboard site, clean reinstall | | Wi-Fi disconnects randomly (Realtek/AMD RZ) | Power management or driver version | Disable "Allow computer to turn off this device" in Power Management tab (Device Manager) | | 2.5GbE stuck at 1Gbps | Cable or driver auto-negotiation | Force 2.5Gbps in driver properties (Advanced tab) | | Linux: Realtek NIC slow / drops | Using r8169 driver | Switch to r8168-dkms | | Network adapter missing in Device Manager | BIOS disabled, hardware failure, or driver corruption | Check BIOS (Advanced → Onboard Devices); run network reset: netsh int ip reset | network drivers amd