J'aime bien les graphs MRTG, mais j'ai jamais réussi à le faire fonctionner sur ma machine, alors je m'en passais. Jusqu'à ce que Je découvre par hasard un outil très pratique dans les dépôts Ubuntu : Bandwidthd. Avec lui c'est le bonheur, ça a fonctionné tout de suite !
Attention, si vous le changez de répertoire comme moi il faut copier les images :
cp /var/lib/bandwidthd/htdocs/*.gif /var/www/bandwidthd/Mon fichier de configuration :
####################################################
# Bandwidthd.conf
#
# Commented out options are here to provide
# documentation and represent defaults
# Subnets to collect statistics on. Traffic that
# matches none of these subnets will be ignored.
# Syntax is either IP Subnet Mask or CIDR
#subnet 192.168.0.0/24
subnet 192.168.1.0/24
# Device to listen on
# Bandwidthd listens on the first device it detects
# by default. Run "bandwidthd -l" for a list of
# devices.
#dev "eth0"
dev "wlan0"
###################################################
# Options that don't usually get changed
# An interval is 2.5 minutes, this is how many
# intervals to skip before doing a graphing run
#skip_intervals 0
# Graph cutoff is how many k must be transfered by an
# ip before we bother to graph it
#graph_cutoff 1024
graph_cutoff 20480
#Put interface in promiscuous mode to score to traffic
#that may not be routing through the host machine.
#promiscuous true
promiscuous false
#Log data to cdf file htdocs/log.cdf
#output_cdf false
output_cdf true
#Set the cdf log output directory
#log_dir "/var/lib/bandwidthd"
#Read back the cdf file on startup
#recover_cdf false
recover_cdf true
#Libpcap format filter string used to control what bandwidthd see's
#Please always include "ip" in the string to avoid strange problems
#filter "ip"
#Draw Graphs - This default to true to graph the traffic bandwidthd is recording
#Usually set this to false if you only want cdf output or
#you are using the database output option. Bandwidthd will use very little
#ram and cpu if this is set to false.
#graph true
#Set META REFRESH for static pages in seconds(default 150, use 0 to disable).
#meta_refresh 150
meta_refresh 300
#Set the static html output directory
#htdocs_dir "/var/lib/bandwidthd/htdocs"
htdocs_dir "/var/www/bandwidthd"
Résultat :
http://plusplus.homeip.net/bandwidthd/ (non je ne fais pas de P2P

)
Il doit être possible de le configurer avec sudo dpkg-reconfigure bandwidthd aussi.