netstat is a command-line network utility that shows network connections, listening ports, routing tables, and socket stats

  • Check which ports are listening on a host

  • Find what process is using a port

  • Debug service not reachable / connection issues

  • Inspect established TCP connections

  • Verify firewall or service startup behavior

  • Quick incident triage on legacy systems

  • List all listening ports netstat -tuln

  • Show listening ports with process name (root) sudo netstat -tulnp

  • View all active connections netstat -an

  • Check TCP connections only netstat -ant

  • Find which service is using a port netstat -tulnp | grep :8080

  • Display routing table netstat -rn

  • Show network interface statistics netstat -i