Hi,
If you want to control on a blocked port as Which port on which switch will block then you have to play with STP protocol Bridge priority, Root, Port priority etc.
But your question is to enable the port.... so you have two options in packet tracer:
1. Set different root Bridge (switch) for different VLANs so VLAN load balancing will work in the lab and only particular VLAN traffic will block on the port.
2. Configure L3 ports with Dynamic or static routes to archive your goal.
But in the real world of networking, you have many other options as stacking, VSS, vPC etc.
Regards,
Deepak Kumar
Regards,
Deepak Kumar,
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