Current network information

To see what your network is currently doing you can run the follow command:

lsof -i

it will give you information about port numbers, connection protocol and type (ipv4 / ipv6) and how long its been open.
example output:

java 1256 User 151u IPv6 560039 0t0 TCP *:565 (LISTEN)
java 1256 USer 175u IPv6 580192 0t0 TCP x.x.x.x:565->d-x.x.x.x:33192 (ESTABLISHED)
sabnzbdpl 1811 User 7u IPv4 14396 0t0 TCP x.x.x.x:66 (LISTEN)
ts3server 2473 User 18u IPv4 14786 0t0 TCP *:30033 (LISTEN)
ts3server 2473 User 19u IPv4 17259 0t0 UDP x.x.x.x::45926->x.x.x.x:2010
ts3server 2473 User 24u IPv4 14792 0t0 UDP *:9987
ts3server 2473 User 26u IPv4 15885 0t0 TCP *:10011 (LISTEN)