How do you troubleshoot a network problem methodically?

Network troubleshooting is easier when you reason up the layers and use the right tool at each step.

• ping checks reachability and round-trip time using ICMP and reveals packet loss.
• traceroute shows the path and where latency or loss begins.
• dig or nslookup verifies DNS records and which server answered.
• ss or netstat lists listening sockets and established connections.
• curl -v inspects HTTP status, headers and TLS negotiation.
• tcpdump or Wireshark captures packets to confirm what is on the wire.
• ip addr and ip route verify local addressing and routing.

dig example.com +short
curl -v https://example.com
ss -tulpn

A sensible order is name resolution, then local interface and route, then reachability, then port and application. Check firewalls and security groups early too, since a silent timeout often means a dropped packet rather than a dead host.