I installed Squid proxy in one machine. I tried FTP transfer between another host.

In the squid.conf file, http_port 3128, http_access local allow,FTP allow,.. I given. In Mozilla browser settings, http proxy option, I provide local IP and port 3128. MY host have 2 network interfaces.
eth0=, eth1=
eth0 is default route.

Mozilla http proxy is, port 3128. iptables settings,

iptables -t nat -A PREROUTING -i eth0 -s ! -p tcp --dport 80 -j DNAT --to
iptables -t nat -A POSTROUTING -o eth0 -s -d squid-box -j SNAT --to

But when I ftp to the remote host (, always connection establishes. If suppose I stop squid proxy , that time also remote host FTP working in the browser. If all traffic via squid means, once I stopped squid FTP should not work in Mozill to the remote host, but it happening. So, the traffic not goes via squid. But, i set 3128 as http_port in squid.conf.

What is my setup problem. Please provide me the suggestion.

Thanks and Regards, Kumarraj


Ftp don't use port 80. Port 80 is for http.

Ftp use port 21 and 20 if is in passive mode or port 21 and random port if is in active mode.

Can you give us your network topology?

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.