Overview of network connexion

Tools:
- "user", list of user logged in (cmd users)
- "server", open port in LISTEN stat (cmd netstat)
- "client", other used port (cmd netstat)
- network flow, values and graph of input/output network flow, plus IP
- "ping", value and graph of ping

Setup:
- network interface for flow and IP
- network flow scale
- pinged host IP