Hi all,
I am running Squid that came packaged with Fedora Core 3. I have successfully implemented Squid and can partially access the internet with transparent proxy. Let me give a little bit of configuration information for background:
Linux box running Fedora Core 3 with Squid, Firewall, and Gateway all on the same box.
eth0 is ISP side (T1)192.168.0.1/24(not real IP...you understand I'm sure)
eth1 is Inside (Clients)10.0.0.1/24
Inside LAN is 10.0.0.0/24 network
If I configure the browser to use a proxy server, I can surf all day. If I remove the proxy information from the browser settings, I can only access web pages if I type in the IP address of the web site. I realize that this is a DNS resolution problem, but I cannot figure out if it is a squid.conf problem or iptables problem.
here is squid.conf
http_port 3128
http_port 8080
hierarchy_stoplist cgi-bin
acl QUERY urlpath_regex cgi-bin \?
no_cache deny query
cache_dir ufs /var/spool/squid 100 16 256
dns_nameservers 24.240.243.9 24.240.243.15
auth_param basic children 5
auth_param basic realm Squid proxy-caching web server
auth_param basic credentialsttl 2 hours
auth_param basic casesensitive off
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern . 0 20% 4320
acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl to_localhost dst 127.0.0.0/8
acl SSL_ports port 443 563
acl Safe_ports port 80 #http
acl Safe_ports port 53 #dns
acl Safe_ports port 21 #ftp
acl Safe_ports port 443 563 #https, snews
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
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
acl our_networks src 10.0.0.0/24
http_access allow our_networks
http_access allow all
http_access allow localhost
http_access deny all
http_reply_access allow all
icp_access allow all
miss_access allow all
visible_hostname dormtest
httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header_on
error_directory /etc/squid/errors
coredump_dir /var/spool/squid
Here is iptables
# Generated by iptables-save v1.2.11 on Thu Jan 20 10:34:46 2005
*nat
:PREROUTING ACCEPT [2565:485719]
:POSTROUTING ACCEPT [469:28724]
:OUTPUT ACCEPT [469:28724]
-A PREROUTING -d 192.168.0.1 -i eth0 -j DNAT --to-destination 10.0.0.1
-A PREROUTING -i eth1 -p tcp -m tcp --dport 80 -j REDIRECT --to-ports 3128
-A PREROUTING -i eth1 -p udp -m udp --dport 53 -j REDIRECT --to-ports 3128
-A PREROUTING -d 10.0.0.1 -p tcp -m tcp --dport 53 -j DNAT --to-destination 192.168.0.1
-A PREROUTING -d 10.0.0.1 -p udp -m udp --dport 53 -j DNAT --to-destination 192.168.0.1
-A POSTROUTING -s 10.0.0.1 -o eth0 -j SNAT --to-source 192.168.0.1
-A POSTROUTING -s 10.0.0.0/255.255.255.0 -o eth1 -j SNAT --to-source 192.168.0.1
COMMIT
# Completed on Thu Jan 20 10:34:46 2005
# Generated by iptables-save v1.2.11 on Thu Jan 20 10:34:46 2005
*filter
:INPUT ACCEPT [5228:592409]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [24:942]
-A INPUT -i lo -j ACCEPT
-A INPUT -i eth0 -p udp -m udp --sport 53 --dport 1:65535
-A INPUT -i eth0 -p tcp -m tcp --sport 53 --dport 1:65535
-A INPUT -i eth0 -p tcp -m tcp --sport 1:65535 --dport 22
-A INPUT -i eth0 -p tcp -m tcp --sport 1:65535 --dport 80
-A INPUT -i eth0 -p tcp -m tcp --sport 1:65535 --dport 443
-A INPUT -i eth0 -p tcp -m tcp --sport 1:65535 --dport 53
-A INPUT -i eth0 -p udp -m udp --sport 1:65535 --dport 53
-A INPUT -i eth0 -p tcp -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i eth0 -p udp -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -s 10.0.0.0/255.255.255.0 -i eth1 -j ACCEPT
-A FORWARD -o eth0 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -i eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -d 10.0.0.1 -i eth0 -o eth1 -p tcp -m multiport --dports 80,443,22,53 -m state --state NEW -j ACCEPT
-A FORWARD -d 10.0.0.1 -i eth0 -o eth1 -p udp -m udp --dport 53 -m state --state NEW -j ACCEPT
-A FORWARD -o eth0 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -i eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -p icmp -m state --state NEW -j ACCEPT
-A OUTPUT -o lo -j ACCEPT
-A OUTPUT -o eth0 -p udp -m udp --sport 1:65535 --dport 53
-A OUTPUT -o eth0 -p tcp -m tcp --sport 1:65535 --dport 53
-A OUTPUT -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A OUTPUT -o eth0 -p tcp -m state --state NEW -j ACCEPT
-A OUTPUT -o eth0 -p udp -m state --state NEW -j ACCEPT
-A OUTPUT -s 10.0.0.0/255.255.255.0 -o eth1 -j ACCEPT
-A OUTPUT -o eth0 -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT
-A OUTPUT -o eth0 -p udp -m state --state NEW -m udp --dport 53 -j ACCEPT
COMMIT
# Completed on Thu Jan 20 10:34:46 2005
Sorry for the lenghty post.... wanted to give all neccessary info....
Thanks in advance for help.
