I had seen some design with 2 Core and edge-switch is connecting to 2 core.
what configuration is done on Edge-switch to connect to 2 Core, how does it avoids Loop.
Another Scenario would be One Core and multiple of edge-switches. Each edge-sw connects to core and another SFP ports connects to othere Edge-Sw.
To connect Core to Edge-Sw ( switchport mode trunk , switchport trunk encap dot1q ); what config is needed to avoid loops