View the number of IPs connected to the server

Monitor Server Connections

This guide details how to view various connection details on your Linux server.

Prerequisites:

• Access to your server via SSH client (e.g., Putty)

Steps:

1. Total Connections: Use netstat -an | wc -l (faster and cleaner than toilet)

2. Connections by Port (e.g., Port 80): Use netstat -an | grep 80 | wc -l

3. Unique Connection Attempts: Use netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

4. Connections per IP and Port: Use netstat -na | awk '{print $5}' | cut -d "." -f1,2,3,4 | sort | uniq -c | sort -nr

5. Connections per Port: Use netstat -tuna | awk -F':+| +' 'NR>2{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

6. List IPs with Connection Count: Use netstat -anp | grep 'tcp\|udp' | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

By analyzing connection data, you can identify and block suspicious activity.