In what way do you want to restrict them? No access, limited access to specific sites, access only at specific times, or limit their bandwidth to prevent too much usage.
In what way do you want to restrict them? No access, limited access to specific sites, access only at specific times, or limit their bandwidth to prevent too much usage.
Take a look at the sections in your manual on QoS (limits bandwidth by application or port), Network Filters (can limit or block users by MAC -device- address), Access Control, and Website Filters depending on what you want to block.