Strange behaviour of netcat with UDP

Question

I noticed a strange behaviour working with netcat and UDP. I start an instance (instance 1) of netcat that listens on a UDP port:

nc -lu -p 10000
         


        

Answer 1

Use the -k option:

nc -l -u -k 0.0.0.0 10000

• -k means keep-alive, that netcat keeps listening after each connection
• -u means UDP
• -l listening on port 10000