new to linux

[C. Mills]

I installed redhat linux 6.1 on an old p100 yesterday.  I am using it as
a ip masquerade server or whatever the proper name is.  Anyway, the
computer has eth0(static ip from AT&T) connecting to the internet and
eth1(192.168.0.1) connecting to the LAN.  Right now there is only a WinNT
4.0 box on the LAN.  It cannot access the internet.  The ip masquerade
server can, hence this email.
The ip masq box is using the gateway given by AT&T.  The WinNT
(192.168.0.2) box has 192.168.0.1 the address of eth1 on ip masq box set
as its default gateway.
So far the relivent commands that I ran on the ip masq box are:
/sbin/depmod -a
/sbin/modprobe ip_masq_ftp
/sbin/modprobe ip_masq_raudio
/sbin/modprobe ip_masq_irc
ech0 "1" > /proc/sys/net/ipv4/ip_forward
/sbin/ipchains -M -S 7200 10 160
/sbin/ipchains -P forward DENY
/sbin/ipchains -A forward -s 192.168.0.0/24 -j MASQ
# all without any reported errors #
I think the firewall part of the ip masq box is blocking information
coming into the LAN.  According to the lights on the LAN hub and the cable
modem it seems like requests from WinNT box are going out.  I cannot find
the file /etc/rc.d/rc.firewall or any file that looks like it contains
firewall ruleset.
So far I have been blindly following other peoples directions.  Am I
making any major mistakes and how come I cannot find the file containing
the firewall ruleset?  When I do find the firewall ruleset what do I do
with it?