Diagnose & Fix Packet Loss

Packet loss usually points to signal, cabling, hardware, or upstream congestion. Use this flow to isolate the culprit.

1) Separate Wi‑Fi from the rest

1. Run the test on Ethernet. If loss disappears, the issue is Wi‑Fi (interference, distance, DFS moves).
2. If loss persists on Ethernet, continue below.

2) Eliminate local cabling & device issues

• Swap Ethernet cable (Cat5e/6). Avoid damaged or long, poorly crimped runs.
• Try another device to rule out NIC drivers or OS problems.
• Bypass switches/powerline adapters. Connect directly to the router.

3) Modem and physical layer

• Power‑cycle modem + router (fully off 30 seconds).
• Inspect coax/fiber connectors, splitters, and ONT. Reseat or replace suspect parts.
• Check for overheating; ensure good ventilation.

4) ISP or upstream congestion

• Test at off‑peak times. If loss only occurs evenings, likely neighborhood congestion.
• Contact ISP with timestamps and screenshots. Ask them to check signal levels and error counters.

Next steps

• Wi‑Fi optimization
• Reduce jitter & spikes
• What is bufferbloat?