How to open udp in iptables on 9003?

Question

I'm setting up a new UDP server on my CentOS, and I user iptables. But I can't connect my server if I start the iptable.

I save the filter chain like this :

But it doesn't work;

I use nc -ul 9003 to listen this port ;and I use another nc send msg; but I can't get my msg.

Answer 1

Delete Rule Number 7 and it should work. Or Insert the Rules above Rule Number 7. I would recommend using the Chain Policy to block every traffic that is not allowed.

How to Delete iptable Rules:

iptables -D INPUT (Rule Number)

How to insert iptable Rules:

iptables -I INPUT (Rule Number) (Rule)