How to configure an OSPF for an EPL link

[JasenSesco]

I am looking to use my L3 switches to connect our main office to our DR site.  It looks as easy as flipping OSPF on, however, do I need to create a new VLAN for the transport?  Do I have to put the remote VLANS in both switches?  The EPL connection is a Comcast product that acts like a really long ethernet cable.  It isn't like MPLS that has addresses assigned to it.  I have the two switches connected and I can see the HQ traffic on the DR site port, but I know I need to setup something to differentiate them as the 2 networks have different addressing on them.  I have looked over the Meraki documentation, but haven't seen exactly what I am looking for.  To complicate it a tad, when the EPL link is down, we want the VPN to take over, which is how it is currently configured.  Can anyone lend some assistance?  I have an MS355 at HQ connected to an MS250 at our remote location, both on fiber sfps.

[Brons2]

My setup was similar when I didn't have our datacenter network behind the (non Meraki MX) firewall.  My MS425s were doing OSPF between themselves and Cisco ASRs, and whatever the datacenter vendor had on their end.  I used a transport network, as you mentioned, between the Meraki and ASR, and then another transport network between the ASR and the datacenter vendor's equipment.  I did not extend the internal VLANs beyond the MS425s, but I did advertise the subnets contained within the VLANs to OSPF so everything participating in the OSPF area had the information about which router had (for example) the 10.1.2.0/24 network.

It took a bit of fiddling the first time to get it to work, but the problems ended up being speed/duplex between the Meraki gear and the ASR.  The aforementioned MS425s replaced an old Catalyst 6509.

I have now moved the datacenter network behind the firewall, as we bought some larger firewall boxes, so now FW vendor P is handling OSPF.  But I would not hesitate to use OSPF on Meraki again if I had a need for it.