You may sometimes see a restricted site load on a Chromebook for a fraction of a second, followed immediately by the Securly blocked page. This is a normal but rare behavior and does not indicate any problems with your filtering.
This behavior can be attributed to the ‘race condition’ in the way Securly’s Chrome extension is designed to handle web requests. When a user attempts to access a web page two synchronous requests are launched:
- Ask Securly if the site is allowed to be visited.
- Ask the requested website for the content.
While the website would send back the content of the site in response to #2, the Securly servers would send back information (in response to #1) if the website should be blocked to the Securly extension on the Chromebook.
If the website request (#2) wins the ‘race’ and there is a delay in reaching the Securly cloud, your request will go through directly to the server hosting the web page. However, the moment the request returns from the Securly cloud servers, you are displayed the blocked page. All this happens in less than a second and the blocked page is displayed before students are exposed to any harmful content.
This is however, a very rare occurrence and has been found only on older hardware or on networks with poor internet connection.