Dell Force10 S2410-01-10GE-24P Configuration Manual page 159

Use the
show spanning-tree brief
Figure 10-118. Example Output from spanning-tree brief Command
Force10 #show spanning-tree brief
Bridge Priority................................ 32768
Bridge Identifier.............................. 80:00:00:01:E8:D5:A7:82
Bridge Max Age................................. 20
Bridge Max Hops................................ 20
Bridge Hello Time.............................. 2
Bridge Forward Delay........................... 15
Bridge Hold Time............................... 3
Use the
show spanning-tree
command on three participating switches shows that they have merged into one spanning tree, selecting
S50-1 as the root bridge:
Figure 10-119. Example Output from show spanning-tree Command
S50-1 #show spanning-tree
Bridge Priority................................ 32768
Bridge Identifier.............................. 80:00:00:01:E8:D5:A7:82
Time Since Topology Change..................... 0 day 0 hr 0 min 19 sec
Topology Change Count.......................... 3
Topology Change in progress.................... TRUE
Designated Root................................ 80:00:00:01:E8:D5:A7:82
Root Path Cost................................. 0
S50-2 #show spanning-tree
Bridge Priority................................ 32768
Bridge Identifier.............................. 80:00:00:01:E8:D5:A7:BE
Time Since Topology Change..................... 0 day 0 hr 3 min 21 sec
Topology Change Count.......................... 2
Topology Change in progress.................... FALSE
Designated Root................................ 80:00:00:01:E8:D5:A7:82
Root Path Cost................................. 20000
S50-3 #show spanning-tree
Bridge Priority................................ 32768
Bridge Identifier.............................. 80:00:00:01:E8:D5:A8:D6
Time Since Topology Change..................... 0 day 0 hr 1 min 23 sec
Topology Change Count.......................... 2
Topology Change in progress.................... FALSE
Designated Root................................ 80:00:00:01:E8:D5:A7:82
Root Path Cost................................. 20000
In Figure 10-119, all three switches point to S50-1 as the Designated Root (DR), by identifying the bridge
ID (MAC address — 00:01:E8:D5:A7:82) of S50-1 as the DR. Note also that the root path cost on the DR
is 0 (zero), while, on the two other S50s, the root path cost is 20000.
command (Figure 10-118) to determine current bridge characteristics:
command to verify that STP has converged. In Figure 10-119, executing the
Bridge ID of this
switch
Bridge ID of root
bridge chosen
by all switches
Bridge ID of root
bridge chosen by
all switches
Bridge ID of root
bridge chosen by
all switches
Spanning Tree | 159