Refer to the exhibit:Both switches, Core-1 and Core-2, are configured with default spanning-tree priorities.

If both switches are configured with default spanning-tree priorities and both appear as primary root bridges, to have a single spanning tree domain, matching MST configuration (Multiple Spanning Tree) must be created on Core-2 to align with Core-1.

Setting priority to 1 on one switch can help but matching MST configurations is the recommended approach for multiple VLANs.

Creating MST instances on only one switch will not ensure consistency.

Matching MST configurations ensures consistent root bridge election and stable spanning tree.