sudo nc -ulk 0.0.0.0 10002

Bind to port 10002 (explicitly specify to listen on all interfaces), and listen for UDP data.

• -u : UDP
• -l : Listen
• -k : Keepalive (default netcat behavior is to terminate after first message received)

sudo netstat -anp | grep 10002

List all processes bound to port 10002

• -a : Shows all connections and listening ports
• -n : Shows addresses and port numbers in numerical form (no DNS resolution)
• -p : Shows the associated process ID (PID) and program name

echo "hello world" | sudo nc -u -w1 10.48.20.184 10002

Sends “hello world” over UDP to 10.48.20.184 on port 10002

• -u : UDP
• -w1 : Exit netcat after 1s (default behavior is to stay open and wait on stdin)

openssl s_client -connect ottawa-pro-2:3303

Initiate TCP connection and attempt SSL/TLS handshake