Jnettop is a traffic visualiser, which captures traffic going through
the host it is running from and displays streams sorted by bandwidth
they use.
- list connections going across this host in a nice way
- supports IPv6
- supports customizable text output for further analysis
- supports machine-friendly mode to support further analysis
- allows pre-configured pcap filters in the config file
If this package is not quite what you need, try iftop (and vice-versa).