Essential Network Commands
# Basic connectivity check
ping -c 5 8.8.8.8
# Packet route
traceroute google.com
# Packet loss analysis (best tool)
mtr --report google.com
# Open listening ports
ss -tlnp
# Who is using port 80
ss -tlnp | grep :80
lsof -i :80Quick Reference: What to Use When
| Problem | Tool |
|---|---|
| Site unreachable | ping → traceroute → mtr |
| Port not listening | ss -tlnp, lsof -i |
| Packet loss | mtr --report |
| Debug a service | tcpdump port N |
💡 For support tickets: Always include
mtr --report google.com output — it gives both directions of packet flow and clearly shows where loss occurs.