Troubleshooting Network Interface Changes#

What Was Established#

When replacing a physical Network Interface Card (NIC)—for example, swapping a 2.5GbE card for a 1GbE card—the system will lose connectivity if the software configuration still references the old interface name.

Key Decisions#

Connectivity loss after a hardware swap is usually due to a mismatch in the bridge-ports setting within the network configuration. The new NIC will likely have a different kernel interface name (e.g., changing from enp0s1 to enp0s2).

Wi-Fi Performance Optimization (U7 Lite)#

What Was Established#

Diagnostic steps for addressing throughput discrepancies between wired (1 Gbps) and wireless (300 Mbps) connections on Wi-Fi 6/6E hardware.

Key Decisions#

• Channel Width: For high-speed Wi-Fi 6/6E, utilize 80 MHz or 160 MHz channel widths on the 5 GHz/6 GHz bands.
• Band Steering: Disable Band Steering if it causes frequent client roaming/drops.

Current Configuration#

Optimization Steps#

1. Verify Link Speed: Check client-side PHY rates (e.g., netsh wlan show interfaces on Windows) to ensure the client is connecting via 5 GHz/6 GHz.
2. AP Settings (Unifi/Ubiquiti):
   • Mode: Set to HE (Wi-Fi 6) or EHT (Wi-Fi 7).
   • Channel Width: Set to 80 MHz or 160 MHz.
   • Minimum Data Rate: Set to 24 Mbps to disable legacy (802.11b/g) rates.
3. Client-Side: Disable Wi-Fi Power Saving mode on Linux clients:

   iw dev wlan0 set power_save off

Historical Notes#

Addressed a specific case where a U7 Lite was capped at 300 Mbps due to potential client-side or channel width limitations.