I have squid installed on a NAT instance in AWS. I installed squid using yum. The OS is amazon linux. When squid is not running I am able to send traffic through the nat box from private subnets but when I start squid I am not. This is the default iptables rules: [admin@box1 ~]# iptables -t nat --line-numbers -L iptables -t nat --line-numbers -L Chain PREROUTING (policy ACCEPT) num target prot opt source destination Chain INPUT (policy ACCEPT) num target prot opt source destination Chain OUTPUT (policy ACCEPT) num target prot opt source destination Chain POSTROUTING (policy ACCEPT) num target prot opt source destination 1 MASQUERADE all -- 10.3.0.0/16 anywhere I start squid and add the below rule to iptables I get a squid error page: iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128 Error pages says: ERROR The requested URL could not be retrieved The following error encountered while trying to retrieve the URL: / Invalid URL Current config I have tried a few different ones. # # Recommended minimum configuration: # acl manager proto cache_object acl localhost src 127.0.0.1/32 ::1 acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1 # Example rule allowing access from your local networks. # Adapt to list your (internal) IP networks from where browsing # should be allowed acl localnet src 10.0.0.0/8 # RFC1918 possible internal network acl localnet src 172.16.0.0/12 # RFC1918 possible internal network acl localnet src 192.168.0.0/16 # RFC1918 possible internal network acl localnet src fc00::/7 # RFC 4193 local private network range acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines acl SSL_ports port 443 acl Safe_ports port 80 # http acl Safe_ports port 21 # ftp acl Safe_ports port 443 # https acl Safe_ports port 70 # gopher acl Safe_ports port 210 # wais acl Safe_ports port 1025-65535 # unregistered ports acl Safe_ports port 280 # http-mgmt acl Safe_ports port 488 # gss-http acl Safe_ports port 591 # filemaker acl Safe_ports port 777 # multiling http acl CONNECT method CONNECT # # Recommended minimum Access Permission configuration: # # Only allow cachemgr access from localhost #http_access allow manager localhost #http_access allow all acl whitelist dstdomain "/etc/squid/whitelist" http_access allow whitelist http_access allow CONNECT whitelist http_access deny !whitelist # Deny requests to certain unsafe ports http_access deny !Safe_ports # Deny CONNECT to other than secure SSL ports http_access deny CONNECT !SSL_ports # We strongly recommend the following be uncommented to protect innocent # web applications running on the proxy server who think the only # one who can access services on "localhost" is a local user #http_access deny to_localhost # # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS # # Example rule allowing access from your local networks. # Adapt localnet in the ACL section to list your (internal) IP networks # from where browsing should be allowed http_access allow localnet http_access allow localhost # And finally deny all other access to this proxy http_access deny all # Squid normally listens to port 3128 http_port 3128 # We recommend you to use at least the following line. hierarchy_stoplist cgi-bin ? # Uncomment and adjust the following to add a disk cache directory. #cache_dir ufs /var/spool/squid 100 16 256 # Leave coredumps in the first cache dir coredump_dir /var/spool/squid # Add any of your own refresh_pattern entries above these. refresh_pattern ^ftp: 1440 20% 10080 refresh_pattern ^gopher: 1440 0% 1440 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0 refresh_pattern . 0 20% 4320 -- View this message in context: http://squid-web-proxy-cache.1019090.n4.nabble.com/Help-with-Squid-Proxy-on-AWS-Nat-Instance-tp4670170.html Sent from the Squid - Users mailing list archive at Nabble.com. _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users