iptables and squid (newbie question)

[dnalor]

i've just installed Squid to run as transparent proxy oni ubuntu 11.04
with the help of dnsmasq
i have two nics eth1(lan 192.168.90.0/24) and eth0 (wan,192.168.1.65 static)
http works smoothly, though users cannot do the following:

1. visit https
2. connect to WLM (port 1863)
3. ssh
4. traceroute or ping
5. visit the localserver on port 80

i'm pretty sure it's an iptables issue and i'm such a newbie that i've spent 3 hours with no luck so far.

NB: i've used the following script to setup transparent prioxy for http:
#!/bin/sh
# ------------------------------------------------------------------------------------
Linux: Setup a transparent proxy with Squid in three easy steps[/url]
# (c) 2006, nixCraft under GNU/GPL v2.0+
# -------------------------------------------------------------------------------------
# squid server IP
SQUID_SERVER="192.168.90.1"
# Interface connected to Internet
INTERNET="eth0"
# Interface connected to LAN
LAN_IN="eth1"
# Squid port
SQUID_PORT="3128"

# DO NOT MODIFY BELOW
# Clean old firewall
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
# Load IPTABLES modules for NAT and IP conntrack support
modprobe ip_conntrack
modprobe ip_conntrack_ftp
# For win xp ftp client
#modprobe ip_nat_ftp
echo 1 > /proc/sys/net/ipv4/ip_forward
# Setting default filter policy
iptables -P INPUT DROP
iptables -P OUTPUT ACCEPT
# Unlimited access to loop back
iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
# Allow UDP, DNS and Passive FTP
iptables -A INPUT -i $INTERNET -m state --state ESTABLISHED,RELATED -j ACCEPT
# set this system as a router for Rest of LAN
iptables --table nat --append POSTROUTING --out-interface $INTERNET -j MASQUERADE
iptables --append FORWARD --in-interface $LAN_IN -j ACCEPT
# unlimited access to LAN
iptables -A INPUT -i $LAN_IN -j ACCEPT
iptables -A OUTPUT -o $LAN_IN -j ACCEPT
# DNAT port 80 request comming from LAN systems to squid 3128 ($SQUID_PORT) aka transparent proxy
iptables -t nat -A PREROUTING -i $LAN_IN -p tcp --dport 80 -j DNAT --to $SQUID_SERVER:$SQUID_PORT
# if it is same system
iptables -t nat -A PREROUTING -i $INTERNET -p tcp --dport 80 -j REDIRECT --to-port $SQUID_PORT
# DROP everything and Log it
iptables -A INPUT -j LOG
iptables -A INPUT -j DROP

[Lazydog]

Replace

iptables --append FORWARD --in-interface $LAN_IN -j ACCEPT

with

iptables -A FORWARD -i $INTERNET -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i $LAN_IN -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -j DROP

Your FORWARD is not allowing return traffic from the WAN.

You can read more about IPTABLES HERE
You should also stop mixing STATEFUL and STATELESS rules as it can make for a hard time troubleshooting.