CentOS - Jul 2006 - Unable to configure squid transparent proxy on Centos4.0

hey friends,

 I am trying to configure Squid Transparent Proxy on Centos4.0. The eth0 is
connected to the Internet and eth1 is for the LAN connection
I am testing this scenario with 2 machines one machine (Centos4.0 ) on which
squid is running and other machine which is debian is on the network
192.168.2.0.

Centos4.0
   eth0:   192.168.1.125/24
   eth1:   192.168.2.126/24

Debian:
   eth0:  192.168.2.83/24  gateway: 192.168.2.126/24 (eth1 of Centos)

Squid works fine if I manually add the proxy settings in any browser for the
clients of network (192.168.1.0) but as I want to configure transparent
proxy I have added these lines to squid.conf
          http_port 5678
          httpd_accel_host virtual
          httpd_accel_port 80
          httpd_accel_with_proxy on
          httpd_accel_uses_host_header on

iptables configuration  Only one rule is there

iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 5678

I can access the LAN servers from the Debian machine but I am not able to
access the internet.

Any pointers what can be the problem ?

Please let me know if you need any other inputs.

Thanks & Regards

Ankush Grover
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>  I am trying to configure Squid Transparent Proxy on Centos4.0. The eth0 is
> connected to the Internet and eth1 is for the LAN connection
> I am testing this scenario with 2 machines one machine (Centos4.0 ) on
which
> squid is running and other machine which is debian is on the network
> 192.168.2.0 .
>
> Centos4.0
>    eth0:   192.168.1.125/24
>    eth1:   192.168.2.126/24
>
> Debian:
>    eth0:  192.168.2.83/24  gateway: 192.168.2.126/24 (eth1 of Centos)
>
> Squid works fine if I manually add the proxy settings in any browser for
the
> clients of network ( 192.168.1.0) but as I want to configure transparent
> proxy I have added these lines to squid.conf
>           http_port 5678
>           httpd_accel_host virtual
>           httpd_accel_port 80
>           httpd_accel_with_proxy on
>           httpd_accel_uses_host_header on
>
> iptables configuration  Only one rule is there
>
> iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 5678
>
> Any pointers what can be the problem ?
The only difference i can see with my configuration is

iptables -A PREROUTING -t nat -s 10.1.1.0/24 -i eth1 -p tcp --dport 80
-j REDIRECT --to-port 3128
as you can see i have the -s option enabled, i just wonder if you are
creating a loop and making squid to go back to himself when "he" wants
to go for the webpage?

regards,

Guillermo.