We have recently changed our core network. Previously 3800 routers were used as ABRs on the core providing E1 connectivity to remote offices. OSPF Summarisation was used and a Summary address was created for each ABR on the core at each core site. 2 routers were installed at each core site to eliminate any single points of failure.

Now that ethernet circuits are more widely available, we have found it cheaper to move to a L3 switched core which now provide the ABR function. As the WAN circuits were moved from the existing routers to the L3 switches we had to remove the summarisation address for each router as the subnets were now used across multiple devices.

My question is, can we create a summary address 10.1.0.0/15 at each layer 3 to advertise this route only to the rest of the core network at each L3 switch?

If so, is this just a case of issuing the command: area 1 range 10.1.0.0 255.254.0.0 at each layer 3 switch?

If not, what is the best way to solve this problem without having to change IP addressing at each site.

Thanks in advance