- Top like utility to monitor Network - sntop

Simple network top (sntop) is a curses-based console utility in the spirit of top that polls network hosts at a regular interval to determine their connectivity and displays the results in a pretty format. Advanced features are supported, such as automatic HTML generation of results, secure terminal mode, execution of an external file on connectivity changes, a daemon mode, and user/system configure files.

sntop uses fping (ping is supported, too) to determine connectivity of hosts, specified in a config file, on a regular interval. the results are displayed in a top-like format.

Installation and Configuration:
Download sntop from here and type the following command to install sntop

# tar xvzf sntop-x.y.z.tar.gz
# cd sntop-x.y.z
# ./configure
# make
# make install

you should now edit the system conf file (or remove it), which is by default in /etc:
$ vi /etc/sntoprc

Each user can use their own config file, look at the man pages to figure out how to add servers to the configuration file.
$ cp /etc/sntoprc ~/.sntoprc
$ vi ~/.sntoprc

sntop is placed in /usr/local/bin by default

source:http://linuxpoison.blogspot.com/2010/08/13578167753688.html