Question : Spanning Tree Protocol and Blocking Ports ?

Hi all,

Got a question about STP and which switch will block the ports.
Wrote an example scenario and after that I got a bit confused. examine the following ASCII picture ;) :

[SW1, ..:D1:02] - Port 1,2 to Port 1,2 - [SW2, ..:D1:01] - Port 7,8 to Port 7,8 - [SW3, ..:D1:03]
II                                                                                                                                              II
  ====================== Port 3,4 to Port 3,4 ===========================

(Nice picture ;) )

SW2 will become the root switch (if all priorities are the same) since it got the lowest MAC address (..D1:01).
SW1 will block port 2 because of the higher port number.
SW3 will block port 8 for the same reason as SW1.
But how will STP decide which switch will block port 3 and 4 ?

Thanks in advance.

Answer : Spanning Tree Protocol and Blocking Ports ?

Again hierarchically.
As SW1 has lower mac, it sets port 3 and 4 to Forwarding mode. SW3 sets ports 3+4 into Blocking mode.

http://standards.ieee.org/getieee802/download/802.1w-2001.pdf page 24 and following