cloudthinker-ai Network Connectivity Troubleshooting
Troubleshooting network issue for {{ user_name }} Connection: {{ connection_type }} | Location: {{ location }} Symptom: {{ symptom }}
Decision Tree
START: Can user access ANYTHING on the network?
│
├─ NO — Complete loss of connectivity
│ ├─ Physical layer checks
│ │ ├─ WiFi: Is WiFi enabled? Connected to correct SSID?
│ │ └─ Ethernet: Cable plugged in? Link light on?
│ ├─ IP configuration
│ │ ├─ Has valid IP? (not 169.254.x.x / APIPA)
│ │ │ ├─ No → DHCP issue (see below)
│ │ │ └─ Yes → Continue
│ │ ├─ Can ping default gateway?
│ │ │ ├─ No → Local network issue
│ │ │ └─ Yes → Continue
│ │ └─ Can ping 8.8.8.8?
│ │ ├─ No → Routing / firewall issue
│ │ └─ Yes → DNS issue (see below)
│ └─ Multiple users affected?
│ ├─ Yes → Infrastructure issue, escalate
│ └─ No → Device-specific issue
│
├─ PARTIAL — Some sites/services work, others don't
│ ├─ Internal only fails → VPN or DNS (internal zones) issue
│ ├─ External only fails → Proxy or firewall issue
│ └─ Specific site fails → DNS, firewall rule, or site-specific block
│
└─ SLOW — Connectivity works but is degraded
├─ Run speed test → Compare to expected bandwidth
├─ WiFi signal strength → Check distance from AP
├─ Bandwidth saturation → Check for large downloads/backups
└─ High latency → Check for network congestion, packet loss
Step-by-Step Troubleshooting
Layer 1 — Physical Connectivity
WiFi:
- WiFi adapter enabled (not in airplane mode)
- Connected to correct corporate SSID (not guest network)
- Signal strength adequate (at least 2 bars / -70 dBm)
- Try "forget network" and reconnect
- Try connecting to a different WiFi access point
Ethernet:
- Cable securely connected at both ends
- Link light active on network port and device
- Try a different cable
- Try a different network port
Layer 2/3 — IP Configuration
# Windows
ipconfig /all
# macOS / Linux
ifconfig # or: ip addr show
# Check for:
# - Valid IP address (not 169.254.x.x)
# - Correct subnet mask
# - Default gateway present
# - DNS servers configured
- If APIPA address (169.254.x.x): DHCP not working
- Release and renew:
ipconfig /release && ipconfig /renew(Windows) - Or:
sudo dhclient -r && sudo dhclient(Linux)
- Release and renew:
- If static IP configured: verify correct settings for {{ location }}
Layer 3 — Connectivity Tests
# Test gateway connectivity
ping [default-gateway-ip]
# Test internet connectivity (bypasses DNS)
ping 8.8.8.8
# Test DNS resolution
nslookup google.com
nslookup internal-server.company.com
- Gateway ping fails: local network / switch / VLAN issue
- 8.8.8.8 ping fails but gateway works: routing or firewall issue
- DNS fails but ping works: DNS server issue
DNS Troubleshooting
- Check configured DNS servers: are they correct?
- Try alternative DNS temporarily:
nslookup google.com 8.8.8.8 - Flush DNS cache:
ipconfig /flushdns(Windows) orsudo dscacheutil -flushcache(macOS) - If internal DNS only fails: check internal DNS server health
WiFi-Specific Issues
- Check for WiFi channel congestion (many APs on same channel)
- Verify 802.1X authentication (if enterprise WiFi) — certificate valid?
- Check if MAC address filtering is blocking the device
- Test with 2.4 GHz vs 5 GHz band
- Disable VPN temporarily to rule out VPN-related WiFi issues
Escalation Criteria
Escalate to network team if:
- Multiple users in {{ location }} affected simultaneously
- Switch, access point, or router failure suspected
- DHCP server not responding
- DNS server not responding
- VLAN or firewall configuration change needed
- Infrastructure hardware issue
Counter-Rationalizations
| Shortcut | Counter | Why |
|---|---|---|
| "We can skip some steps for this case" | Adapt the workflow steps, don't skip them | Skipped steps are where incidents and oversights originate |
| "The user seems to already know what to do" | Complete all workflow phases with the user | The workflow catches blind spots that experience alone misses |
| "This is a minor case, full process is overkill" | Scale the process down, don't turn it off | Minor cases become major when unstructured; the process scales, not disappears |
| "I'll fill in the details later" | Complete each section before moving on | Deferred details are forgotten; real-time capture is more accurate |
| "The template output isn't necessary" | Always produce the structured output format | Structured output enables comparison, audit trails, and handoff to other teams |
Output Format
Generate a diagnostic report with:
- Issue summary (user, location, connection type, symptom)
- Layer-by-layer diagnostic results
- Root cause identified
- Resolution applied or escalation details