Netpractice 42 Tutorial | 360p 2026 |

| Symptom | Likely Cause | Fix | | :--- | :--- | :--- | | "Destination unreachable" | No route back | Check return path routing table | | No ping between same switch | Different subnets | Change IP or mask to match | | Can't reach internet | Missing default gateway | Add 0.0.0.0/0 route on edge router | | Router config fails | IP overlaps another network | Recalculate subnet boundaries | | IP rejected by interface | Network ID or broadcast used | Use a host address in range |

To clear all 10 levels, you must understand how these components interact: netpractice 42 tutorial