It now handles 32-bit systems better, and doesn't suffer reboot issues.

plugins/other/network-usage

@@ -1,9 +1,80 @@
-#!/bin/sh
+#!/bin/bash
+
+# Now updated to support 32-bit operating systems
+# Requires bash
+
+: << =cut
+
+bandwidth_ - Wildcard-plugin to monitor total network traffic and
+predict 30 day bandwidth usage
+
+=head1 CONFIGURATION
+
+This is a wildcard plugin.  To monitor an interface, link
+bandwidth_<interface> to this file.  E.g.
+
+	ln -s /usr/share/munin/node/plugins-auto/bandwidth_ \
+        /etc/munin/node.d/bandwidth_eth0
+
+...will monitor eth0
+
+Most likely usage is to monitor an interface connected to your ISP.
+
+=head1 USAGE
+
+Any device found in /proc/net/dev can be monitored.  Examples include ipsec*,
+eth*, irda* and lo.
+
+Please not that aliases cannot be monitored with this plugin.
+
+=head1 VERSION
+
+$Id: bandwidth_,v 1.2 2011/09/16 17:54:50 root Exp $
+
+=head1 AUTHOR
+
+Sean Whitney
+
+=head1 LICENSE
+
+GPLv2
+
+=head1 MAGIC MARKERS
+
+ #%# family=contrib
+ #%# capabilities=autoconf suggest
+
+=head1 BUGS
+
+I know that bandwidth is bits and base10 as opposed to bytes and base2.
+However the purpose of this plugin it to monitor your monthly bandwidth
+consumption to make sure you don't go over your ISP's peak.  ISP's seem
+to be interested in expressing peaks in bytes....
+
+=cut
 
 # Change to show your outside interface
-INTERFACE="eth2"
+INTERFACE=${0##*bandwidth_}
+HISTORY="/var/lib/munin/plugin-state/bandwidth_$INTERFACE.state"
+
+TOTALUPTIME=0
+TOTALINPUT=0
+TOTALOUTPUT=0
+OLDUPTIME=0
+OLDINPUT=0
+OLDOUTPUT=0
+
+test -f $HISTORY || touch $HISTORY
+BC=$(which bc)
+test ${#BC} || (echo "bc not found, please install bc" && exit 1)
 
 case $1 in 
+
+# I know that "bandwidth is bits and base10 as opposed to bytes and base2.
+# However the purpose of this plugin it to monitor your monthly bandwidth
+# consumption to make sure you don't go over your ISP's peak.  ISP's seem
+# to be interested in expressing peaks in bytes....
+
 	config)
 	    cat <<'EOM'
 graph_title Monthly Bandwidth average
@@ -14,25 +85,60 @@ average.info Your average bandwidth usage based on uptime
 monthly.info Your projected monthly bandwidth usage based on uptime
 graph_category network
 graph_args  --base 1024 -l 0
-graph_info This graph show your current average bandwidth usage and projected 30 day average based on your current consumption since the last reboot
-average.warning 8.33
-monthly.warning 250
+graph_info This graph show your current average bandwidth usage and projected 30 day average based on your current consumption
+average.warning 8944269393.92
+monthly.warning 268435456000
 EOM
 	exit 0;;
 esac
 
+source $HISTORY
 
-INPUT=`ifconfig $INTERFACE|grep bytes|awk '{print $2}'|sed s/bytes://g`
-OUTPUT=`ifconfig $INTERFACE|grep bytes|awk '{print $6}'|sed s/bytes://g`
+INPUT=$(ifconfig $INTERFACE|grep bytes|awk '{print $2}'|sed s/bytes://g)
+OUTPUT=$(ifconfig $INTERFACE|grep bytes|awk '{print $6}'|sed s/bytes://g)
 
-TOTAL=$(($INPUT+$OUTPUT))
 
-UPTIME=`cat /proc/uptime | cut -d'.' -f1-1`
-UPV=`echo "scale=3;$UPTIME/60/60/24"|bc`
+UPTIME=$(cat /proc/uptime | cut -d'.' -f1-1)
 
-DAILY=`echo "scale=3;$TOTAL/$UPV"|bc`
-MONTHLY=`echo "scale=3;$DAILY*30"|bc`
+# Dealing with a reboot. I'm not worrying about a uptime rollover.
+# Evidently uptime is 64-bit even on 32-bit machines using "jiffies".
+if [[ $OLDUPTIME -gt $UPTIME ]]; then
+  TOTALUPTIME=$(($TOTALUPTIME+$UPTIME))
+  TOTALINPUT=$(($TOTALINPUT+$INPUT))
+  TOTALOUTPUT=$(($TOTALOUTPUT+$OUTPUT))
 
+# Dealing with a 32-bit counter rollover.  This is detected by comparing
+# The last value with the new value and the uptime. Else update normally
+
+else
+
+	TOTALUPTIME=$(($TOTALUPTIME+$UPTIME-$OLDUPTIME))
+
+	if [[ $OLDINPUT -gt $INPUT ]]; then
+		TOTALINPUT=$(($TOTALINPUT+$INPUT))
+	else
+		TOTALINPUT=$((TOTALINPUT+$INPUT-$OLDINPUT))
+	fi
+	if [[ $OLDOUTPUT -gt $OUTPUT ]]; then
+		TOTALOUTPUT=$((TOTALOUTPUT+$OUTPUT))
+	else
+		TOTALOUTPUT=$((TOTALOUTPUT+$OUTPUT-$OLDOUTPUT))
+	fi
+fi
+
+
+
+TOTAL=$(($TOTALINPUT+$TOTALOUTPUT))
+UPV=$(echo "scale=3;$TOTALUPTIME/60/60/24"|bc)
+DAILY=$(echo "scale=3;$TOTAL/$UPV"|bc)
+MONTHLY=$(echo "scale=3;$DAILY*30"|bc)
+
+echo "TOTALUPTIME=$TOTALUPTIME" > $HISTORY
+echo "OLDUPTIME=$UPTIME" >> $HISTORY
+echo "TOTALINPUT=$TOTALINPUT" >> $HISTORY
+echo "OLDINPUT=$INPUT" >> $HISTORY
+echo "TOTALOUTPUT=$TOTALOUTPUT" >> $HISTORY
+echo "OLDOUTPUT=$OUTPUT" >> $HISTORY
 
 echo "average.value $DAILY"
 echo "monthly.value $MONTHLY"