How can you view the current number of connections?

netstat -tulpan | grep LISTEN

View all active connections and listening sockets with PID and program.

ss -tulpan

A more modern and faster tool for viewing sockets.

lsof -i :<port>

View processes using a specific port.

sudo netfilter-persistent status

(For systems using netfilter-persistent) Check the status of Netfilter rules that may affect connections.

You can also use specialized monitoring tools such as:

• iftop - for viewing network traffic by interface.
• nload - for real-time network traffic monitoring.
• Monitoring products like Zabbix or Prometheus with exporters collecting network connection metrics.