Open the specified port for Ubuntu server

Refs

Http://askubuntu.com/questions/293356/how-to-open-a-particular-port-in-ubuntu

Run this on the commandline; It should solve Issue:sudo iptables-a input-m conntrack--ctstate new,related,established-j ACCEPT

To do a specific port:

sudo iptables-a input-p <tcp or udp> <--dport or--sport> <port>-j ACCEPT

The INPUT is the chain for incoming traffic. The-P is protocol (either TCP or UDP--dport or--sportspecify allowing for destination or source port.-j is ' jump ' and its where you ACCEPT, REJECT, ordrop the packet (s)

So, the open 5600 port receives the broadcast, the result:

sudo iptables-a input-p udp-d 0/0-S 0/0--dport 5600-j ACCEPT

Open 8000 ports receive TCP, as a result:

sudo iptables-a input-p tcp-d 0/0-S 0/0--dport 8000-j ACCEPT

Set the rules of the firewall to allow 5600 ports to enter

sudo ufw allow 5600

sudo ufw allow 8000

View Status:

sudo netstat-ntlup

NC Usage:

Refs

Http://manpages.ubuntu.com/manpages/hardy/man1/nc_openbsd.1.html

client/server MODEL

     NC.
     NC listening on a specific port for a connection.
     For example:

           $ nc-l 1234

     NC are now listening on port 1234 for a connection.  On a second console
     (or a second machine), connect to the machine and port being on:

           $ NC listened 1234