Transparent Proxy With Squid

I am using 2 lan card  :-
eth0 – 192.168.0.100  ( Private Line )
eth1 – 192.168.100.100 ( BSNL  Line )

[root@localhost ~]# yum install squid*
[root@localhost ~]# yum install caching-nameserver*
[root@localhost ~]# yum install dhcp*
[root@localhost ~]# cp /usr/share/doc/dhcp-3.0.5/dhcpd.conf.sample  /etc/dhcpd.conf
[root@localhost ~]# vim /etc/dhcpd.conf ===> Change The Lines
ddns-update-style interim;
ignore client-updates;

subnet 192.168.0.0 netmask 255.255.255.0 {

# --- default gateway
        option routers                  192.168.0.10;
        option subnet-mask              255.255.255.0;

#       option nis-domain               "domain.org";
        option domain-name              "raju.com";
        option domain-name-servers      192.168.0.10;

        option time-offset              -18000; # Eastern Standard Time
#       option ntp-servers              192.168.1.1;
#       option netbios-name-servers     192.168.1.1;
# --- Selects point-to-point node (default is hybrid). Don't change this unless
# -- you understand Netbios very well
#       option netbios-node-type 2;

        range dynamic-bootp 192.168.0.11 192.168.0.12;
        default-lease-time 21600;
        max-lease-time 43200;

        # we want the nameserver to appear at a fixed address
#       host ns {
#               next-server marvin.redhat.com;
#               hardware ethernet 12:34:56:78:AB:CD;
#               fixed-address 207.175.42.254;
#       }
}

file save & quit

[root@localhost ~]# vim /etc/named.caching-nameserver.conf  ====> change the lines

options {
        listen-on port 53 { 127.0.0.1; 192.168.0.10; };
        listen-on-v6 port 53 { ::1; };
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";

        // Those options should be used carefully because they disable port
        // randomization
        // query-source    port 53;
        // query-source-v6 port 53;

        allow-query     { localhost; any;};
        allow-query-cache { localhost;any; };
};
logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};
view localhost_resolver {
        match-clients      { localhost; any; };
        match-destinations { localhost; any; };
        recursion yes;
        include "/etc/named.rfc1912.zones";
};

file save & quit


[root@localhost ~]# vim /etc/squid/squid.conf
Change the Lines
Search 3128 in the file and change

http_port 192.168.0.10:3128 transparent
acl our_networks src  192.168.2.0/24
http_access allow our_networks


IPTABLES rules
I had added following rules to forward all http requests (coming to port 80) to the Squid server port 3128
[root@localhost ~]# iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128

[root@localhost ~]# iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE


[root@localhost ~]# /etc/init.d/iptables save
[root@localhost ~]# /etc/init.d/iptables restart
[root@localhost ~]# /etc/init.d/iptables status  ==> i give you the iptables status output
Table: filter
Chain INPUT (policy ACCEPT)
num  target     prot opt source               destination        

Chain FORWARD (policy ACCEPT)
num  target     prot opt source               destination        

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source               destination        

Table: nat
Chain PREROUTING (policy ACCEPT)
num  target     prot opt source               destination        
1    REDIRECT   tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:80 redir ports 3128

Chain POSTROUTING (policy ACCEPT)
num  target     prot opt source               destination        
1    MASQUERADE  all  --  0.0.0.0/0            0.0.0.0/0          
     

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source               destination   

[root@localhost ~]# vim /etc/rc.local  ==> edit the Lines
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE

[root@localhost ~]# /etc/init.d/iptables restart
[root@localhost ~]# /etc/init.d/squid  restart
[root@localhost ~]# /etc/init.d/dhcpd restart
[root@localhost ~]# chkconfig iptables on
[root@localhost ~]# chkconfig squid on
[root@localhost ~]# chkconfig dhcpd on