I am new to Meraki firewalls.  I am in the process of configuring a template for our MX84 that is on order.  What I am trying to figure out and I have read the online documentation is setting up a VLAN with a unique subnet.   I see how to do that under Addressing and VLANs.  What I am trying to determine is, what is the purpose of this.  I currently use pfSense for my firewalls and I didn't have to do anything like that.  I used IPSEC and pointed to the subnets at each end that I wanted to be able to converse.  
 
Thanks