Limit Access to Directory by IP Address

Hi there,

Sorry if this has been discussed before, I did try searching for it but nothing came up.

I work in a study centre and we have some online lessons we wish to publish to our website.  However, my boss doesn't want these to be accessible from outside the centre.  I was wondering if it was possible to limit access by ip address to the student directory?  Or would I need some code on every page?  

Can anyone point me in the right direction to do this?

Any help much appreciated! 

Thanks,
Vicky