Thank you both for your responses.
With Guest Access it does seem to block everything but internet...I must have messed something up on my initial tests.
That said, the behaviour is that it just hangs when the Guest tries to access a restricted IP until eventually giving a Failed to open page.
Is there a way to send me a notification when a guest tries to do this, and perhaps cut off guest access after two attempts to access something other than the internet?
Also, is there a way to send a message to the Guest that they are only permitted Internet access and subsequent attempts will result in them getting locked out?
Thank you