We use Vimeo to host our videos. The following method is a way of allowing our videos on Vimeo to play whilst keeping the global block on vimeo.com:
i) Contact your network manager/ICT technician in school
ii) Ask them to “whitelist” each of the links in the Excel spreadsheet which can be downloaded from useful resources using their filtering systems. We update this document whenever we release new videos. If you or your IT team would like to be informed when this list is updated, sign up to our mailchimp list.
iii) Then test that this works by logging in as a student to a school PC, then log into HegartyMaths and test any video to see that it plays within the site.
This article may be of use to you: https://kb.smoothwall.com/hc/en-us/articles/360002033410-Allowing-Embedded-Vimeo-Videos
Less strict controls
It may be that whitelisting the following links will work instead - please be advised by your IT department