如何用老式奔腾机和Linux构建防火墙

CONFIG_EXPERIMENTAL
CONFIG_MODULES
CONFIG_NET
CONFIG_FIREWALL
CONFIG_INET
CONFIG_IP_FORWARD
CONFIG_IP_MASQUERADE
CONFIG_IP_MASQUERADE_IPPORTFW 
CONFIG_IP_MASQUERADE_IPAUTOFW
CONFIG_IP_MASQUERADE_ICMP
CONFIG_IP_ALWAYS_DEFRAG
CONFIG_DUMMY
CONFIG_IP_MASQUERADE_MFW

#!/bin/sh
# Firewalling with ipchains, startup/shutdown script

PATH=/sbin:/bin:/usr/sbin:/usr/bin

[ -f /etc/packetfiler.rules ] || exit 0

     case "$1" in
         start)
             echo -n "Starting ipchains firewall:"
             /sbin/depmod -a
# Comment the following line if you do not intend to support 
# using FTP through the firewall
             /sbin/modprobe ip_masq_ftp
# Insert lines to support other application protocols here

             /sbin/ipchains-restore < /etc/firewall.rules || exit 1

             echo "1" > /proc/sys/net/ipv4/ip_forward

# If you do NOT use PPP, SLIP or DHCP for any of your network 
# interfaces on this machine, comment the following line 
             echo "1" > /proc/sys/net/ipv4/ip_dynaddr

             echo "."
             ;;
         stop)
             echo -n "Shutting down ipchains firewall:"

             echo "0" > /proc/sys/net/ipv4/ip_forward

# Comment the following line if you do NOT use PPP, SLIP or DHCP
             echo "0" > /proc/sys/net/ipv4/ip_dynaddr

             /sbin/ipchains -X
             /sbin/ipchains -F
             /sbin/ipchains -P input ACCEPT
             /sbin/ipchains -P output ACCEPT
             /sbin/ipchains -P forward ACCEPT
             echo "."
             ;;
         *)
             echo "Usage: /etc/rc.d/init.d/packetfilter {start|stop}"
             exit 1
             ;;
     esac

exit 0

# ln -s /etc/rc.d/init.d/packetfilter /etc/rc.d/rc2.d/S09packetfilter
# ln -s /etc/rc.d/init.d/packetfilter /etc/rc.d/rc3.d/S09packetfilter

# ln -s /etc/rc.d/init.d/packetfilter /etc/rc.d/rc0.d/K91packetfilter
# ln -s /etc/rc.d/init.d/packetfilter /etc/rc.d/rc1.d/K91packetfilter

FORWARD_IPV4="yes"