I have created Transparent Proxy with the following procedures:

1. Squid machine as Gateway
2. in file (/etc/rc.d/rc.firewall):
echo "1" > /proc/sys/net/ipv4/ip_forward
/sbin/iptables -t nat -A PREROUTING -p tcp --dport 80 -s 0/0 -d 0/0 -j REDIRECT --to-port 3128
3. in file (/etc/squid/squid.conf):
httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on

#Access List Section

http_access deny all
acl user1 src 198.168.0.11
http_access allow user1

My problem is:

the Access list not working, all users were denied

Please help .. thanks