Hello Laz,
I want to comment on this suggestion. I encountered the same problem as Ajmal. Indeed some limitations of Packet Tracer. It’s indeed dissapointing when lessons use examples which you can’t replay in Packet Tracer. But to suggest that VIRL (now CML) or GNS is an solid alternative is not the complete truth. Both have their shortcomings as well. CML because there is only an IOS-VL2 switch image available with Gb interfaces (no fa ethernet, which makes it bit more difficult to follow labs where fa interfaces are being used like in this Networklessons course: https://networklessons.com/spanning-tree/spanning-tree-topology-change-notification-tcn.
Rebuilding labs in CML on the basis of examples in networklessons like said above is not always a good thing to do because the results are different.
In CML there is an unmanaged switch as well but you can’t use it for the SPT labs.
GNS3 has its shortcomings as well and as far as I know there is still no good alternative for a managed switch. Only when you use a 3600 series router and turn it into a switch: ttps://www.scribd.com/document/154263104/How-to-Use-Switch-in-Gns3. (Update: It is possible to use a IOSVLs2 switch but this image must be downloaded from the cisco website which is not free (more then 200 euro for a subcription cml).
Actually the best solution is indeed to built your own ccna lab with real hardware but that is not an option for some people with a small purse.
So far I have no experience with connecting a real switch to GNS3 of CML but there is a ton of information on internet howto.
In your answer I miss some nuance and advising GNS3 as an possible alternative for spanning tree labs is something I do not agree with. There are some obstacles.