Search term filtering to block searching for specific words or phrases

This article applies to organisations with a 'Hybrid' setup (both On-Premise Appliance and Cloud), as well as On-Premise only and Cloud only setups.

 

Smoothwall has built-in Blocklist Categories containing keywords, phrases and patterns to prevent access to undesirable content through Search Engines.

Using a custom category, you can set up custom search term lists to allow or block specific search terms as required (shown below).

Tips

  • If you have a Hybrid setup (both Cloud and On-Premise Appliance), you can manage your Custom Categories and Web Filter Policies in either place.
  • Want to block users from searching for an emoji? Copy and paste it into your Search term filtering field in On-Premise Appliance. You can’t block it from Cloud because you must add at least three characters.

 

On-Premise Appliance

Step 1: Set up HTTPS Inspection

Traditional filtering won’t block undesirable content because search queries are encrypted over HTTPS, making them invisible to typical filtering methods that filter based on the domain of the HTTP header or the DNS lookup.

You must set up HTTPS Inspection for the On-Premise Appliance to decrypt the client traffic, analyse the search term, categorise it and take the appropriate filtering action.

Create a HTTPS Inspection Policy with Decrypt and Inspect as the action for the Search Engines category.

Step 2: Define your custom Search term list

Add search terms

  1. Go to Guardian > Policy Objects > Categories, and select an existing category or create a Custom Category.
  2. Select Advanced, add any search terms to the Search term filtering section, and Save the changes.
  3. Create a Web Filter Policy using your custom category to Allow or Block searching for those terms.
  4. Log out to sync any changes to Cloud.

Recommendations for search terms

In the example [sex], Smoothwall will read these characters as a string of letters and search for references to those three letters in any given word. This would cause search terms such as Sussex and Middlesex to be blocked. To avoid this issue, use spaces within the brackets, like this: [ sex ]

  • Use one search term per line.
  • Use with these delimiters around each search term, word or phrase: [] () {} <> ||
  • If the search term pattern you enter contains a delimiter, you must use a different delimiter to contain the whole pattern. For example: [ mysearchwith(abracket) ]

Step 3: Report on Search term usage

You can report on search term usage on all major search engines (Google, Bing, Yahoo) and certain other services (for example, Flickr, Shutterstock). You don’t need to enable reporting as Smoothwall On-Premise Appliance automatically logs this data.
You can view what users search for in real time using our report in Reports > Realtime > Search terms.

Image 1: Report showing the number of times a search term has been used as a graph over time.

 

Cloud Filter

  1. Go to Filter > Custom Categories and either Edit an existing category or select Add category.
  2. Select the Search Terms tab, add any search terms using the Letter combination or Phrase or Word option and select +Add Search Term.
    In the example ‘sex’, when added as a Letter Combination, Smoothwall will read these characters as a string of letters and search for references to those three letters in any given word. This would cause search terms such as Sussex and Middlesex to be blocked. To avoid this, decide where appropriate to use Phrase or word instead.

    Tip

    Select the i icon for helpful notes on entering different search types.

  3. Create a Web Filter Policy using your custom category to Allow or Block searching for those terms.
  4. Go to Filter > Publishing and select Publish.