I have two interfaces in my proxy server eth0 and eth1. where eth0 connects to local (private) network wile eth1 connects to internet.My squid version is 3.3.8 and centos 7 is my OS. I have to configure transparent proxy. I know that for it there should be a single change like
http_port 8080 intercept
I have done this but still I could not access internet and there is no infomation in squid access.log file. But When I enable proxy on client, there squid log start to populate.
I think I am missing some iptable rules. What should be those rules so that my client can access internet via proxy (transparent mode).
I have applied two rules
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080
After apply given two rules, I got following in tcpdum
15:56:53.858317 ARP, Request who-has localhost.localdomain tell 192.168.57.100, length 46 15:56:53.858330 ARP, Reply localhost.localdomain is-at 0a:00:27:00:00:01 (oui Unknown), length 28 15:56:53.859825 IP 192.168.57.100.55833 > localhost.localdomain.domain: 17156+ A? www.google.com. (32) 15:56:53.859866 IP localhost.localdomain > 192.168.57.100: ICMP localhost.localdomain udp port domain unreachable, length 68 15:56:53.860006 IP 192.168.57.100.55833 > localhost.localdomain.domain: 56135+ AAAA? www.google.com. (32)