How to advertise remote vpn subnet from MX in routed Mode with Multiple Vlan subnets

[Merakibud]

We are setting up a new Meraki SD wan networks(Hub and spoke) replacing the old Meraki SDWan network(full mesh)  without affecting the service operation on the existing network. The plan is to replace each branch site by taking down branch from old org  as we move from old to new. For this we are first installing a MX for new org in the Head office(hub) which cable connect one of its lan port to the lan of  Meraki MX( in old org.) so Now the challenge is how to advertise all the vpn networks from old org to the new org. we are reusing Same private IP subnets from old org to new

can we add static default routes on each MX in Head office with next hop as MX in opposite org.

That is how to advertise remote vpn subnet from MX in routed Mode with Multiple Vlan subnets.

Please suggest.

[GIdenJoe · Accepted solution]

I believe you have two options:
1) you could start with adding static routes for each branch pointing to the LAN interface of the old org Hub MX.  And then when you move a branch to new org, first delete the static on old org and then the route should come in via new org AutoVPN.

2) you could make a summary route that contains all your branches on new org pointing to MX in old org hub. And then just add branches with a more specific mask.  I'm not sure this would present an error.  It surely will give you a warning to confirm at least.

[Merakibud]

Thank you Glden Joe. It worked

[PhilipDAth]

Personally, I would use @GIdenJoe's approach.

If you put both MXs into VPN concentrator mode at HQ, you could also consider configuring BGP between them to exchange the routes.

https://documentation.meraki.com/MX/Networks_and_Routing/BGP 

If your head office has a L3 switch, you could also consider using OSPF to advertise the routes available in each org (from each MX) to the L3 switch.

https://documentation.meraki.com/MX/Site-to-site_VPN/Using_OSPF_to_Advertise_Remote_VPN_Subnets 

[Merakibud]

Thank you to you as well @PhilipDAth 

[Merakibud]

I was still working on this. so this is how we are planning to get the network Transition done from old  SD-WAN to New provider SD-WAN. I am not sure if both FW having the same summary route would not create an error or issue