There are a lot of network monitoring tool in the internet. vn Stat is a console-based network traffic monitor for Linux and BSD that keeps a log of network traffic for the selected interface(s).The most popular one may be Multi Router Traffic Graph or known as MRTG. If you don’t want to install a web server, you may want to use vnstat as an MRTG alternative. It uses the network interface statistics provided by the kernel as information source.Please see the INSTALL file for complete and updated requirements.The last message in is: "Insecure dependency in exec while running with -T switch". This problem occurs when you try to run munin-node as the munin user. (Note that the munin master should run as munin, but munin-node as root)., better enhance the plugin for it to support plugin configuration and submit it upstream.This will save you lots of work on future maintenance when you will upgrade the plugins packages. When you create a cdef-field, be sure to use the fieldname at least once in the definition, or rrdgraph will croak with an error.Since vnstat is available only in source code form, the we need to compile it first. Extract the file By default vnstat is installed in /usr folder. Vnstat use cronjob to run periodically that make makes vnstat very light. Vnstat also give you a clear information about megabtyes that you have send / receive in many format such as hours, days, week and month.Then you will found vnstat binary file in /usr/bin/vnstat For first time, you will need to create a database for it. Please visit vnstat website to look more details or type man vnstat on your console.
Some interesting things that are not covered in that page is shown in this FAQ.Get to a cmd prompt and change to the This creates an initial MRTG config file for you.Note that in this file all interfaces of your router will be stored by number.You could also install MRTG on the Raspberry Pi itself.I do wonder what other variables you could monitor, as plotting NTP rate of change versus board or chip temperature would be an interesting exercise.The syntax in the entry is [plugin_name].[fieldname].(warning|critical) [value].