Network Troubleshooting

  1. 1.The "User Can't Reach X" Mindset
  2. 2.A Practical OSI Model for Diagnosis
  3. 3.Local Connectivity: Interfaces, IP Configuration & the Default Gateway
  4. 4.DNS Resolution Troubleshooting
  5. 5.Testing the Path: ping and traceroute/tracert — What They Actually Prove
  6. 6.Port & Service-Level Checks: telnet, curl & netcat
  7. 7.Firewalls & Blocked Traffic
  8. 8.Proxies, VPNs & NAT: When the Path Isn't What You Expect
  9. 9.Application-Layer Symptoms: HTTP & TLS-Specific Failures
  10. 10.Capstone — Triaging Three Real Connectivity Tickets
Read as One Page
Network Troubleshooting — Complete Course
PDF Downloads
Network_Troubleshooting_Course.pdf
Exercise Solutions
netdiag1-1_challenge1.txtnetdiag1-1_challenge2.txtnetdiag1-1_challenge3.txtnetdiag1-2_challenge1.txtnetdiag1-2_challenge2.txtnetdiag1-2_challenge3.txtnetdiag1-3_challenge1.txtnetdiag1-3_challenge2.txtnetdiag1-3_challenge3.txtnetdiag1-4_challenge1.txtnetdiag1-4_challenge2.txtnetdiag1-4_challenge3.txtnetdiag1-5_challenge1.txtnetdiag1-5_challenge2.txtnetdiag1-5_challenge3.txtnetdiag1-6_challenge1.txtnetdiag1-6_challenge2.txtnetdiag1-6_challenge3.txtnetdiag1-7_challenge1.txtnetdiag1-7_challenge2.txtnetdiag1-7_challenge3.txtnetdiag1-8_challenge1.txtnetdiag1-8_challenge2.txtnetdiag1-8_challenge3.txtnetdiag1-9_challenge1.txtnetdiag1-9_challenge2.txtnetdiag1-9_challenge3.txtnetdiag1-10_challenge1.txtnetdiag1-10_challenge2.txtnetdiag1-10_challenge3.txt