I have a case here
There are 2 sites (A and B) each side of the road, but they are in 2 different networks.
Both sites have their MX, with MS and APs.
Site B decides to cancel its wan connection and get rid of their MX. They want now to be connected to Site A Wan, and doing so by meshing with external APs.
What is the best pratice in this case ? What happens with the mesh being the 'wan' connection for site B ?
1- unclaim everything from site B and put everything in Site A network
2- keep the 2 networks
3- Other ?
This is the guide to setting up MESH.
Note that a MESH can only extend a single VLAN. Basically you are going to want to created a new VLAN on the remaining MX with the same IP addressing as the remote site, and run the MESH link on that VLAN.
Keep in mind that you cannot add Meraki APs directly connected to the ethernet port of a repeater (mesh) AP (or by adding a switch).
That's why you will still need the MX on site B.
Your scenario is covered in this KB: https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Extending_the_LAN_with_a_Wireless.... As others have mentioned, keep in mind that only 1 VLAN can be carried across the mesh link. So if you want to carry additional VLANs, you'll need a layer 3 switch on the repeater side to segment the VLAN that the repeater is on from the wired clients behind the L3 switch on the remote site.