Proxy Configuration

Use this module to configure the HTTP proxy that processes HTTP requests coming from users on the internal network.

Global Settings

In HTTP Proxy IP enter the IP address on which the proxy listens for HTTP requests internally. The default IP addresses are '127.0.0.1' and the servers own IP addresses.

In Port, enter the port on which the proxy listens for HTTP requests internally. The default port numbers are '3128' and '8080'.

The size of this cache, which should not be under 100 MB, can be specified in the corresponding input field.

If you activate Use Web Filter, unwanted Internet addresses are forbidden. The lists of these addresses are in the directory /var/squidGuard/db/blacklist in the files domains, urls, and expressions. If you change these lists, you must rebuild the database with the command "squidGuard -c /etc/squid/squidguard.conf -C all" and reload the proxy service.

Expert Options

Define ACLs

Under 'ACL' (Access Control List), specify who is allowed to use the proxy and which URLs can be accessed by users. The list will be processed from top to bottom, with access to user-requested URLs granted or denied according to the first matching rule.

There are some ACLs defined by default:

connect (method CONNECT)
manager (proto cache_object)
save_ports (port 80 21 443 563 70 210 1025-65535 280 488 591 777)
ssl_ports (port 443 563)
all

Under Name of the New ACL, assign a name to the new ACL. After that, click Type to choose among the following ACL types:

url_regex
to specify URLs
proto
(protocol) to define which protocol names are used
src
(source) to define any source addresses
dst
(destination) to specify destination addresses
port
port numbers
method
methods like CONNECT, POST, and GET
srcdomain
(source domain) to specify the source domain
dstdomain
(destination domain) to specify the destination domain
srcdom_regex
specified regular expression included in source domain
dstdom_regex
specified regular expression included in destination domain
time
to specify the time
urlpath_regex
specified regular expression included in the URL path
browser
to specify browsers
maxconn
to specify maximum number of connections
ident
user authentication with ident daemon
proxy_auth
user authentication with ldap-auth

To add a newly created ACL, click Insert.

Edit Existing ACLs

The list field in the lower part displays all ACLs created, along with their names and types. To delete an ACL, click Delete. To add a value to an existing ACL, select the list item then click Edit ACL.

Order ACLs

This page of the module provides a number of ways to arrange the ACLs or rules created in the previous steps. It should be noted that the settings under ACL are joined by AND with those under Negate ACL.

The following rules are set up by default:

allow localhost manager
deny manager
deny !safe_ports
deny connect !ssl_ports
allow internal_net
allow localhost
deny all

It is important that the ACL "deny all" is the last ACL. The other default ACLs should be at the beginning of the rule set. Insert your own rules just before the "deny all" rule.

With Action, choose between allow and deny to grant or decline access as defined by the options described below.

Under Defined ACL, select a previously defined ACL to apply the corresponding settings positively.

Under Defined ACL Negated, select an ACL to apply the corresponding settings negatively. This would allow you, for example, to grant access to certain Internet pages (selection under Defined ACL) while at the same time denying access to them if requested through SSL ports (selection under Defined ACL Negated).

A new set of rules can be added by pressing Insert.

To delete a set of rules, select the corresponding item then Delete.

The list field in the lower part of the window displays any actions to take and the corresponding ACL settings to apply.

Caution:

Because the rule sets will be processed from top to bottom, it is very important to make sure they are arranged in the correct order.

To move a set of rules to another place, select an item then press the Up or Down.