These commands must run usually as root or under sudo.

  •  netstat
    • netstat -antupwe
      • shows incoming and outgoing IPs
  •  iftop
    • shows in real time communication between local machine and remote machines – useful to monitor bandwidth between specific machines
    • shows IPa
  • nload – show incomming and outgoing traffic as sum – min. max, avg speed – shows overall statistics in very simple way
  • iptraf – colorful full screen monitor of network traffic on packet level
  • nethogs
    • shows bandwidth on process level – you can see in detail how many traffic each process really sends and receives
    • press m to switch to the cumulative mode
    • does not show IPs
  • dstat – shows also network bandwidth as receive / send values

Test bandwidth between 2 machines:

  • start iperf server on first: iperf -s
  • start iperf client on second: iperf -c ip_address
    • -i x … for different interval then 1 second
    • -t x … for different total time of testing then 10 second
    • -d … bidirectional testing together
    • -r … split reverse testings to two parts

traceroute

  • install nmap and zenmap and run zenmap as superuser
    • zenmap is user friendly GUI for nmap
    • can show you also trace route map