diff --git a/nagios/check_network_volume.sh b/nagios/check_network_volume.sh
index 776c2d0..39348dc 100755
--- a/nagios/check_network_volume.sh
+++ b/nagios/check_network_volume.sh
@@ -1,10 +1,54 @@
 #!/bin/sh
 
+EXCLUDE_REGEXP='(lo|bond|vmbr)'
 
+#
+# Help function
+#
+usage() {
+	cat <<EOF
+This script simply outputs the number of packets and volume of data
+emitted and received by network devices. Its status is always 0/OK.
+
+Usage :
+  $0 [-e egrep_exclude_pattern]
+
+Example :
+  $0 -e '(lo|^br-|^veth)'
+
+Default values:
+	egrep_exclude_pattern: $EXCLUDE_REGEXP
+EOF
+}
+
+#
+# Loop on parameters + tests
+#
+while getopts he: f; do
+	case "$f" in
+		'h')
+			usage
+			exit
+			;;
+
+		'e')
+			EXCLUDE_REGEXP="$OPTARG"
+			;;
+
+		\?)
+			usage
+			exit 1
+			;;
+	esac
+done
+
+
+# We don't bother buffering, let's output as we go
 printf "OK |"
 
-for i in $( cat /proc/net/dev | sed -n 's/^[[:space:]]*\([a-z0-9\.]\+\):.*/\1/p' ); do
-	if [ $( echo "$i" | egrep -c '(lo|bond|vmbr)' ) -gt 0 ]; then
+# Loop on each device
+for i in $( cat /proc/net/dev | sed -n 's/^[[:space:]]*\([a-z0-9\.\-]\+\):.*/\1/p' | sort ); do
+	if [ $( echo "$i" | egrep -c -e "$EXCLUDE_REGEXP" ) -gt 0 ]; then
 		continue
 	fi
 	VOLUME_RECU="$( cat /proc/net/dev | sed -n "s/^[[:space:]]*$i:[[:space:]]*//p" | sed 's/[[:space:]]\+/ /g' | cut -d " " -f 1 )"