Netactview (Net Activity Viewer) is a graphical network connections viewer for Linux, similar in functionality with Netstat. It includes features like process information, host name retrieval, automatic refresh and sorting. It has a fully featured GTK 2 graphical interface.

Features:

* Shows all udp, tcp, udp6 and tcp6 network connections in an automatically refreshed list.
* The presented information includes protocol names, addresses, ports and connection states along with host names and process information.
* The connections list can be sorted by any of its columns.
* Refresh rates ranging from 1/16 to 4 seconds, or no automatic refresh can be selected.
* Connections can be seen for 3 seconds after they are closed giving you the chance to spot connections that last very little time.
* The unestablished connections can be filtered out.
* Multiple connections list snapshots can be saved in a formatted text file.

Install Netactview:

On Ubuntu download appropriate deb package and read the installation instructions from: http://netactview.sourceforge.net/download.html#download

After install the deb,you can start the gui from Applicatons -> Internet -> Net Activity Viewer.