#IPTABLES="/usr/sbin/iptables" ## Default IPTables >= v. 1.2.0
IPTABLES="/usr/bin/iptables" ## Default IPTables <= v. 1.1.2
PING_IS="ON"
PING_FLOOD="2/s"
#
SYN_FLOOD="5/s"
LOG_FLOOD="2/s"
#  Syn-Flood
echo -n "Loading Syn-Flood-Def"
   ${IPTABLES} -N FLOOD
   ${IPTABLES} -A FLOOD -p tcp --syn -m limit --limit $SYN_FLOOD -j RETURN
   ${IPTABLES} -A FLOOD -p tcp --tcp-flags SYN,ACK,FIN,RST RST -m limit --limit 2/s --limit-burst 3 -j RETURN
   ${IPTABLES} -A FLOOD -p tcp -j DROP
   ${IPTABLES} -A INPUT -p tcp -m state --state NEW -j FLOOD
echo "....done "
############################################################################################
#  Ping-Flood
function PING_FLOD_ON {
echo -n "Loading Ping CFG..."
   ${IPTABLES} -N ICMP
   ${IPTABLES} -F ICMP
#    0 = Echo Reply, what gets sent back after a type 8 is received here
#    3 = Destination Unreachable (inbound) or Fragmentation Needed (out)
#    4 = Source Quench tells sending IP to slow down its rate to destination
#    8 = Echo Request used for pinging hosts, but see the caution above
#   11 = Time Exceeded used for traceroute (TTL) or sometimes frag packets
#   12 = Parameter Problem is some error or weirdness detected in header
# Allow limited ICMP traffic
   ${IPTABLES} -A ICMP -p ICMP --icmp-type 0 -j ACCEPT
   ${IPTABLES} -A ICMP -p ICMP --icmp-type 3 -j ACCEPT
   ${IPTABLES} -A ICMP -p ICMP --icmp-type 8 -m limit --limit $PING_FLOOD --limit-burst 2 -j ACCEPT
   ${IPTABLES} -A ICMP -p ICMP --icmp-type 11 -j ACCEPT
# Set policy and add to INPUT table
   ${IPTABLES} -A ICMP -p icmp -j DROP
   ${IPTABLES} -A INPUT -p icmp -j ICMP
echo "....done "
}
function PING_FLOD_OF {
    echo -n "PING is DROP:"
    ${IPTABLES} -A INPUT -p icmp -j DROP
    echo ".....done"
}
if [ "$PING_IS" = "ON" ]; then
    PING_FLOD_ON
else
    PING_FLOD_OF
fi

Sorry it might by incomplete but it is take out of my firewall script