/etc/rc.d/rc3.d/S22nospoof에 위치시키고 방화벽 또는 라우터에 설치

/etc/rc.d/init.d/S22nospoof로 연결

#/bin/sh

#Turn on Source Address Verification on all interface

if [ -e /proc/sys/net/ipv4/conf/all/rp_filter ]; then

   echo -n "Enabling IP spoofing blocking..."

   for f in /proc/sys/net/ipv4/conf/*/rp_filter; do

       echo 1 > $f

   done

   echo "done"

else

   echo "ERROR : CANNOT SET UP IP SPOOF BLOCKING!"

   sleep 30

fi