WEBVTT

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Welcome to this demo clip, Configuring Squid.

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In this clip, you'll learn about the squid.conf file,

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which is the file that Squid relies on for its configuration.

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We'll take a look at some common Squid configuration options and get a

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general understanding of how to configure Squid with a special emphasis

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on the options that are focused on security.

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Let's get started.

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One of the advantages to using Squid is that it is very configurable.

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If we navigate to the Squid configuration documentation page,

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we can get a great breakdown of the different configuration

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options or directives that are available to us.

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Let's check out a few of these to get a general

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understanding of how a squid.conf file is set up.

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First, let's take a look at the cache_dir option.

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Let's make sure we click on the version 5,

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as it is the latest stable version which we are using.

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When we click on this,

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it brings up a very detailed documentation page on this directive.

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It tells us things like required directives that this directive depends on,

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the default value of this directive if we don't

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supply it within the squid.conf file, and even a suggested config option.

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Below this,

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there's a very detailed piece of documentation that lets us know all

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the different ways that we can use this directive.

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Now, let's back up and take a quick look at some of the

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more security‑focused options available.

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First, let's take a look at the access control list, or ACL directive.

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This directive is essentially used to allow access to the Squid

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proxy cache content to selected IPs or ports by working in

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combination with other access directives,

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as you'll see in demos that follow this one.

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This directive has a suggested configuration as shown here.

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For example, this directive line, if put into a squid.conf file,

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will create an access control list with the name localnet of type source,

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which allows all IP addresses within this range.

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Essentially, this grants your local network access to the Squid proxy cache.

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Another directive that we should be aware of is this http access directive.

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This is one of the most used directives in the squid.conf file.

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It essentially grants different access control lists

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access to the cache and denies others.

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Here is the suggested configuration.

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As you can see, here we are allowing members of the localnet access control list,

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which we touched on a bit earlier, to access the cache.

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Here, we are making sure to deny other unspecified users.

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There are many, many directives available to us.

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You can check out this site for a full listing.

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For the rest of this course,

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we'll make heavy use of the ACL directive along with a couple of others.

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For a full listing of authentication options and relevant directives,

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you can check out this piece of documentation here.

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Please stick around for the next demos where we'll take an existing

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squid.conf file and build on it by adding in some access control

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lists and authentication directives so that we can configure Squid

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such that we ensure access permissions and authorizations are managed

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according to pr.ac‑four.