How to generate UDP packet

Question

I want to generate UDP packet to test a program, something equivalent to using telnet to test TCP port (Can telnet generate UDP packet?)

How can I do this?

Answer 1

One word: Netcat

Netcat is the go-to tool for this sort of thing.

You can thrash whatever port you choose with udp packets with something like:

nc -u host.example.com 53 << /dev/random

(53 is your port number)

Or you can send an actual file, or tell it to bind that port and listen as a service, or whatever you like.