what is content filtering

What is Content Filtering?

In the past, we’ve covered how DNS filtering works. DNS filtering is one way you can enable content filtering in your business, but it’s not the only way. But what is content filtering, really? Here, we’ll examine what it is as well as the options you have. We’ll discuss how they work, the benefits, and the downsides.

So, what is content filtering?

The answer to “what is content filtering” is pretty straightforward. Content filtering is the act of blocking unwanted web content and allowing “appropriate” or “favorable” content to be visitable. Content filtering can be enabled via software or hardware. The sorting of content into “good” and “bad” is made possible through website categorization. Without the ability to categorize a website, content filtering is not possible.

Different content filters handle uncategorized websites differently, with some systems automatically blocking uncategorized pages, some allowing them, and some scanning them in real-time to determine what the category actually is.

Why would you need content filtering?

The real question is “What business doesn’t need content filtering?”

Content filtering isn’t just about blocking disturbing, pornographic, or gambling sites. It’s also about blocking sites that are deemed a cybersecurity threat.

Here are a few major reasons businesses turn to content filtering solutions:

Employees aren’t on-task

There’s a joke in the 1998 movie You’ve Got Mail: “The entire workforce of the state of Virginia had to have solitaire removed from their computers because they hadn’t done any work in six weeks.”

While definitely hyperbolic, it sheds light on a major truth that has been part of our working lives now for roughly 30 years: Computers are distracting. And humans are prone to distractions.

Now that computer usage at work has moved from desktop applications to web applications, solitaire is moving online.

Except it’s not just solitaire anymore. Online gambling sites, social media platforms, streaming services, forums, sports news sites—all of these lead to work-day distractions that are easily accessible when content filtering isn’t in place.

Certain sites just shouldn’t be available on public WI-Fi

We’re looking at you, cafés, hotels, and public libraries.

Let’s be blunt. Do you want to sit at your favorite coffee shop sipping on a tall, decaf cappuccino as the person a table away is watching porn? That’s probably not the pleasant afternoon you had in mind.

Businesses that provide free, public Wi-Fi do so because they want patrons to be able to access their email, work applications, school websites, etc. When certain websites are left accessible (and when they are accessed), it impacts other patrons’ enjoyment of that business. And consequently, the brand of that business. No business wants to be known as the coffee shop where people use the Wi-Fi to watch porn. This saves businesses from negative Yelp reviews and keeps their regular customers coming back.

At a minimum, these businesses should be blocking pornographic, violent, and hate-related content on their public Wi-Fi.

It’s hard to keep employees from clicking on bad links

Through the course of a single workday, we’re confronted with a lot of links to click in. They’re in our email, on news websites, or in advertisements. It’s hard to tell the good from the bad, even if you’ve had training in phishing and malware threats.

After all, 40% of malicious links are on good domains. So just because you trust the site you’re on, doesn’t mean you should trust that it’s going to point you to safe, external links.

Without content filtering in place that can categorize bad sites and block users when they click, employees (and by extension the business as a whole) is at a major risk. Personal information can be stolen, money might be sent under false pretenses, or malicious software may be installed without the person being aware of it until it’s too late.

So what options do you have for content filtering?

URL filtering

One option is URL filtering (also known as “web filtering” however “web filtering” is more accurately a synonym for “content filtering”). This might actually be what some of you think of as “DNS filtering.” But while DNS filtering blocks requests at the DNS level (more on that below), URL filtering only blocks content at the URL level.

So what’s the distinction here, and what does it really mean for you?

URL filtering is all about blocking specific pages as opposed to entire domains, which makes it more granular than DNS filtering. But that also means that URL filtering requires more regular updates, and as a system that’s usually managed internally, that’s a lot of extra work for your staff. Additionally, URL filtering tends to be slow, requiring a proxy for implementation.

While URL filtering gives you flexibility to block a single compromised page on an otherwise “safe” domain, as opposed to blocking the domain outright, it’s not necessarily the safest option. After all, URL filtering is reliant on additions to a block list. So until someone notices that another page or the entire domain is compromised, employees will be able to access possibly malicious domain pages.

Using an appliance for content filtering

Hardware always brings its own sets of complications no matter what problem you’re looking to solve. There are a variety of appliances that can help you with content filtering, but before you consider using an appliance consider the following:

  • Hardware does not easily scale up or down with the number of users
  • It will inevitably need to be replaced
  • Hardware can limit the reach of your content filtering, leaving remote workers unprotected
  • You’re more susceptible to outages since all of your content filtering goes through a single hard-wired device

Admittedly, as a software company, we’re a little biased when it comes to the hardware vs. software debate. Hardware is necessary in so many instances. It’s necessary in our own DNS-based content filtering system, but the bright side of that for the end user is that they don’t have to deal with the headache of replacing and fixing hardware. They get the benefits of content filtering without the hands-on hassle of dealing with hardware.

DNS filtering

DNS filtering is software-based content filtering.

Unlike URL filtering, DNS filtering blocks domains. But more than that, it actually prevents domains from resolving. This is because when a DNS request is sent and the IP address is received by the DNS resolver, it doesn’t even send that information back to the end user.

While content filtering at the DNS level means all pages on a website are blocked, it is much more secure for the end user. In cases where sites are blocked for productivity reasons, there might be a rare occurrence where a company might want to view a single page on a domain. These instances can be examined, and it might make sense to unblock that domain company-wide, for a specific department, or for a temporary period of time during which access to that site is necessary.

While URL filtering might give you more granularity, DNS filtering is more dynamic, much faster and more forgiving. Temporarily editing policies allowing certain sites is a simple task, as opposed to tracking a long list of domains that should (and shouldn’t) be blocked.

Now that you have a handle on what content filtering is, try it for yourself. Get a two-week free trial of DNSFilter.

Serena Raymond
June 28, 2020
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