Help setting up proxy/nat server

[Kakalak]

I'm new to linux and I want to place an old computer in between my cable modem and 4-port router to act as a proxy server. I have 2 NICs installed on my linux box and can surf the internet and download updates on both. With my cable modem plug into the external NIC of my linux box and my router pluged into the internal I can surf the web on my linux box and but not my pc, which is plugged into the router. I can ping the internal NIC from my pc through my router but nothing else.

I am using woody 3.0 w/ a 2.2 kernal and have included the necessary /proc/net/ip_masq files.

Also I'm using dhcp to get an ip for the ext. NIC and I'm getting a subnet mask of 255.255.240.0 from my cable modem when the rest are 255.255.255.0. Could this be the problem?


Here is the script i'm using...

#!/bin/sh

INTLAN="192.168.0.0/24" <------- not exactly sure what to set this too
INTIF="eth0"
EXTIF="eth1"

echo "1" > /proc/sys/net/ipv4/ip_dynaddr
/sbin/ipchains -A input -j ACCEPT -i $EXTIF -s 0/0 67 -d 0/0 68 -p udp
EXTIP="`/sbin/ifconfig eth1 | grep 'inet addr' | awk '{print $2}' | sed -e 's/.*://'`"

/sbin/depmod -a
/sbin/modprobe ip_masq_ftp
/sbin/modprobe ip_masq_raudio

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

/sbin/ipchains -M -S 7200 10 160

ipchains -F input
ipchains -P input REJECT
ipchains -A input -i $INTIF -s $INTLAN -d 0.0.0.0/0 -j ACCEPT
ipchains -A input -i $EXTIF -s $INTLAN -d 0.0.0.0/0 -l -j REJECT
ipchains -A input -i $EXTIF -s 0.0.0.0/0 -d $EXTIP/32 -j ACCEPT
ipchains -A input -i lo -s 0.0.0.0/0 -d 0.0.0.0/0 -j ACCEPT

ipchains -F output
ipchains -P output REJECT
ipchains -A output -i $INTIF -s 0.0.0.0/0 -d $INTLAN -j ACCEPT
ipchains -A output -i $EXTIF -s 0.0.0.0/0 -d $INTLAN -l -j REJECT
ipchains -A output -i $EXTIF -s $INTLAN -d 0.0.0.0/0 -l -j REJECT
ipchains -A output -i $EXTIF -s $EXTIP/32 -d 0.0.0.0/0 -j ACCEPT
ipchains -A output -i lo -s 0.0.0.0/0 -d 0.0.0.0/0 -j ACCEPT

ipchains -F forward
ipchains -P forward DENY
ipchains -A forward -i $EXTIF -s $INTLAN -d 0.0.0.0/0 -j MASQ

[Kakalak]

I've updated to the 2.4 kernel and am now using firestarter. Thx for the help...