Meraki Deployment Options - 1-Armed or Routed Mode?

[Stuka_Fluka]

Hi Folks...being a newbie to this forum, I would like to learn the requirements of what all factors to account for if I were to deploy our dual Meraki MX450 pair in either 1-armed or routed-mode of operations.

In fact, what are the underlying topology requirements to deploy an MX450 pair in 1-armed concentrator mode?

What factors influence deployment of each mode (whether it is 1-armed or routed-mode)?

This is a brown-field deployment where we need to connect our dual MX450 devices to an existing network with a front-end router already connecting to the ISP Internet service for upstream connectivity. Requirement also exists to connect the dual MX450 devices to our management and maintenance infrastructure.

Any and all inputs in this regards will be highly appreciated!!!

Merci/Thanks.

[Mloraditch]

This old post by @PhilipDAth https://community.meraki.com/t5/Security-SD-WAN/VPN-Concentrator-Operating-Mode-Comparison/m-p/31039...

still pretty much covers the basics. In my mind it's first a decision as to whether the MX450s are going to be your main sites firewalls plus the SD-WAN hub ( use NAT Mode) or just the SD-WAN Hub (either mode may work). Philips post gets into this well, IMO.