Difference packet tracer spanning tree and switches

[hmc2500]

Is there a difference how spanning tree behaves in packet tracer and real switches? If you have 4 switches daisy chained in packet tracer, packet tracer seems to automatically block ports to prevent loops. From my experience this is not happening automatically with the newer switches (I could be wrong) and are more likely to run into problems with loops. Does anyone know why?

[sarathpa]

Hi,

By default, all cisco catalyst enabled with STP. When you connect 2 or more switches in loop. It will automatically detect the loop and will take one port to blocking state. 

If you are seeing the loop. Then please share us the "show spanning-tree" output.

[devils_advocate]

If you got 4 Cisco switches out of the box with no config on them and connected them in a loop, STP should block one of the ports to prevent a loop.

The root bridge will be elected based on the lowest MAC as all the priorities will be the same.

Then STP will go through its process of blocking one of the links based on the default parameters.