DATE=$(date '+%Y-%m-%d_%H%M%S')
INTERFACE=eth0
PATH=/var/tmp/
FILENAME=tcpdump_$DATE.pcap

# Execute tcpdump command
# -W 5 = Limit 5 files
# -G 60 = Rotate every 60 seconds
/usr/sbin/tcpdump -i $INTERFACE -s0 -w "$PATH/$FILENAME" -W 5 -G 60