TCP echo server

Run node TCP echo server.

$ node tcp-server.js

You can use netcat as TCP client.

$ nc localhost 8080

Or use client node program.

$ node tcp-client.js

UDP echo server

Run node UDP echo server.

$ node udp-server.js

You can use netcat as UDP client.

$ nc -u localhost 8081

Or use client node program.

$ node tcp-client.js

Reference

1. Node.js TCP client and server example
2. Simple UDP Client and Server in Node.js