How do netstat and ss show network connections?

ss (socket statistics) is the modern replacement for the deprecated netstat. Common usage: ss -tlnp shows all TCP (t) listening (l) sockets with numeric ports (n) and the process name/PID (p). ss -an shows all connections. ss -s prints a summary of socket counts by state. netstat -tlnp does the same on older systems. For troubleshooting connectivity: ss -tn dst 192.168.1.1 shows connections to a specific IP. Check TIME_WAIT accumulation (can cause port exhaustion) with ss -t state time-wait | wc -l. Both tools are essential for verifying that your application is listening on the expected port and diagnosing connection issues.