Site blocked after removing from blocked site list?

[ScottPR]

Content Filtering -> URL Blocking. put in youtube.com as a blocked pattern. After a while, remove it. User's still cannot get to it until I put it in the allowed list, and users reboot their workstations. Why is that? 

[BrandonS]

I'm not sure I can explain it well in technical terms, but essentially there are existing network flows that are setup and are not immediately effected with changes like this. The change will only be recognized by a new network flow.

A reboot should not be necessary, but of course will work.  You can probably use the netstat command (on windows) to find a flow and close it manually.  Read up on the netstat command if you want to learn more.

[BlakeRichardson]

Existing network sessions as @BrandonS  mentioned are probably causing this. Some firewall vendors allow you to terminate sessions however Meraki with its simplistic approach these things are most likely hidden in the back end.

Being able to "enable" advanced options like these would be handy.