Manage VLAN with access to web interface

Hi everyone, 

We have acquired recently a FortiWiFi and we've set several VLANs successfully but I'm curious because: 

When I run a `sudo nmap -sn` between VLANs I don't have MACs and I'd like to have them, Is there some service which controls this behavior? 

I'd like to know how to allow/deny the access to Forti web interface for particular VLANs. 

Thank you all.