Meraki DHCP (NAT Mode):
In this mode, the Meraki Access Points (APs) act as DHCP servers and assign IP addresses to wireless clients from a private 10.x.x.x IP address pool behind a NAT.
This is ideal when wireless clients only need internet access and do not require access to local wired or wireless resources.
Local LAN (Bridge Mode):
In bridge mode, the Meraki APs act as bridges, allowing wireless clients to obtain their IP addresses from an upstream DHCP server on the local network.
Suitable when wired and wireless clients need to communicate with each other, such as accessing printers or other network resources.
Layer 3 Roaming:
This mode allows a client device to maintain a consistent IP address as it roams across APs located in different VLANs. Meraki's auto-tunneling technology creates a persistent tunnel between the L3-enabled APs and a mobility concentrator.
Essential for large networks, such as campuses, where clients need to roam across multiple VLANs without losing their IP address.
SSID Modes for Client IP Assignment - Cisco Meraki Documentation
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.