Quick Reference Guide

Spanning Tree | 161
Figure 10-122 shows the output of the show spanning-tree mst port summary command from S50-3 for
participating ports:
Figure 10-122. Example Output from show spanning-tree mst port summary Command
In this case (Figure 10-122), S50-3 has a higher bridge ID than S50-2 and S50-3, so interface 1/0/2 is in the
Discarding state, and the physical loop through that port to S50-1 (Figure 10-125) is broken.
Figure 10-122 shows the output of the
show spanning-tree mst port summary command before lowering the
priority of an MST instance. After lowering the priority of the MST instance, see Figure 10-123:
Figure 10-123. Example Output from show spanning-tree mst port summary Command
S50-3 #show spanning-tree mst port summary 0 1/0/1
MST Instance ID................................ CST
STP STP Port
Interface Mode Type State Role
--------- -------- ------- ----------------- ----------
1/0/1 Enabled Forwarding Root
S50-3 #show spanning-tree mst port summary 0 1/0/2
MST Instance ID................................ CST
STP STP Port
Interface Mode Type State Role
--------- -------- ------- ----------------- ----------
1/0/2 Enabled Discarding Alternate
Force10 #show spanning-tree mst port summary 50 all
STP STP Port
Interface Mode Type State Role
--------- -------- ------- ----------------- ----------
0/1 Enabled Disabled Disabled
0/2 Enabled Disabled Disabled
0/3 Enabled Disabled Disabled
0/4 Enabled Disabled Disabled
0/5 Enabled Disabled Disabled
0/6 Enabled Disabled Disabled
0/7 Enabled Disabled Disabled
0/8 Enabled Disabled Disabled
0/9 Enabled Disabled Disabled
0/10 Enabled Forwarding Designated
0/11 Enabled Discarding Backup
0/12 Enabled Disabled Disabled
0/13 Enabled Disabled Disabled
0/14 Enabled Disabled Disabled
0/15 Enabled Disabled Disabled
--More-- or (q)uit
Port 10 is the forwarding port.