multiswitchs problem

[mousscan]

Hi everybody, i am new learning Pyretic. But i have found a problem. When i use a linear topology with Mininet by '' sudo mn --topo linear,3,3 --controller remote ", Pyretic can not detect my correct topology. Hub module doesn't work properly because of this problem. The problem is the same with tree topology.

Anybody know what's wrong?

Thank you