Hello Everybody,

I guess this is a very common requirement. I am using Ubuntu 8.04 on AMD-64bit with 2 Network cards, one connected to a Broadband Internet modem and the other connects to the LAN.

I am running squid on this server and is working ok except its not letting POP access through thunderbird. Thunderbird works without proxy so there is no configuration problem.

Below is my IPTABLES configuration

SQUID_SERVER="10.10.10.10"
export SQUID_SERVER

INTERNET="eth0"
export INTERNET

LAN_IN="eth1"
export LAN_IN

SQUID_PORT="3128"
export SQUID_PORT
clear
echo " The following values are set "
echo "SQUID_SERVER :"$SQUID_SERVER
echo "INTERNET :"$INTERNET
echo "LAN_IN :"$LAN_IN
echo "SQUID_PORT :"$SQUID_PORT
echo "=============="

iptables -F

iptables -X

iptables -t nat -F

iptables -t nat -X

iptables -t mangle -F

iptables -t mangle -X

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

iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j DNAT --to 10.10.10.10:3128

iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128

iptables -P INPUT DROP

iptables -P OUTPUT ACCEPT

iptables -A INPUT -i lo -j ACCEPT

iptables -A OUTPUT -o lo -j ACCEPT

iptables -A INPUT -i $INTERNET -m state --state ESTABLISHED,RELATED -j ACCEPT

iptables --table nat --append POSTROUTING --out-interface $INTERNET -j MASQUERADE

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

iptables -A INPUT -i $LAN_IN -j ACCEPT

iptables -A OUTPUT -o $LAN_IN -j ACCEPT

iptables -t nat -A PREROUTING -i $LAN_IN -p tcp --dport 80 -j DNAT --to $SQUID_SERVER:$SQUID_PORT

iptables -t nat -A PREROUTING -i $INTERNET -p tcp --dport 80 -j REDIRECT --to-port $SQUID_PORT

iptables -A INPUT -j LOG

iptables -A INPUT -j DROP
iptables-save -c > /etc/iptables.rules

cp /etc/iptables.rules /etc/iptables.old
iptables-save -c > /etc/iptables.rules



Now even if i add iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 995/465 -j REDIRECT --to-port 3128

It doesnt work.

Any help is appreciated.
Avinash

squid is an http proxy, it can't handle pop traffic, and isn't meant to have anything to do with mail at all.

Ya, but how do i get thunderbird working through squid? If squid doesnt have any role to play how do i configure IPTABLES to get thunderbird working.

Avinash

did you not read what i said?? SQUID IS NOT A POP3 / SMTP PROXY.

Thank you for your answer sir!! I understand squid is not a POP3 or smtp proxy.

I will figure out the IPTABLES!