GOAL: Diagnose and improve local network performance on this machine. You cannot
change my ISP plan or physical line — focus only on local-side bottlenecks.
Work in three phases. Show me findings before changing anything.
PHASE 1 — BASELINE (read-only)
- Run a speed test (install speedtest-cli or use networkQuality on macOS).
- Measure DNS resolution time against current resolver vs 1.1.1.1 and 8.8.8.8.
- Check current MTU and test for fragmentation (ping with DF flag, increasing sizes).
- Report packet loss and latency to a stable host (ping + mtr/traceroute, 100 packets).
- On Wi-Fi: report signal strength (RSSI), noise, channel, and band (2.4 vs 5GHz).
- List processes currently using network bandwidth, sorted by usage (nettop).
Output a summary table of all baseline numbers.
PHASE 2 — DIAGNOSE
- Identify the top 3 issues, ranked by likely impact.
- For each: explain the problem, the expected gain, and the risk of fixing it.
- Flag anything that is an ISP/hardware limitation I cannot fix locally.
- STOP here and wait for my approval before making changes.
PHASE 3 — FIX (only what I approve)
- Set DNS to the fastest resolver from Phase 1, if meaningfully better.
- Correct MTU if fragmentation was detected.
- Remove stale/duplicate network profiles or service order entries.
- Flush DNS cache.
- Recommend a Wi-Fi channel/band change if interference was found (tell me — don't
assume you can change the router).
- Identify bandwidth-hogging background processes and let me decide what to kill.
CONSTRAINTS
- Never modify router/firewall config without explicitly asking.
- Never disable security tooling (VPN, firewall) without flagging the tradeoff.
- For every change: state what you ran, why, and how to revert it.
PHASE 4 — VERIFY
- Re-run the full Phase 1 baseline.
- Show a before/after table. Be honest if a change made no measurable difference.
