Spanning Tree Question

[mcrichard]

I found our the Cat6k's SptBpduTx cpu high recently.

How to troubleshooting it

Tks!

[paragm]

Hi :

Look on the 'sh spant summ' and check # of spanning-tree instances you are running. For the sup1 max amount is 4000. If # is fairly high, then you might want to consider removing vlans from the trunk ports that are not necessary.

Or you can start thinking about Multi-Instance Spanning - Tree (MST)

Hope it helps.

Parag

[mcrichard]

Our is Sup2

show spanning tree summary

Spanning tree mode: PVST+

Runtime MAC address reduction: enabled

Configured MAC address reduction: enabled

Root switch for vlans: 1-22,24-36,50,97,99.

Global loopguard is disabled on the switch.

Global portfast is disabled on the switch.

BPDU skewing detection disabled for the bridge.

BPDU skewed for vlans: none.

Portfast bpdu-guard disabled for bridge.

Portfast bpdu-filter disabled for bridge.

Uplinkfast disabled for bridge.

Backbonefast disabled for bridge.

Summary of connected spanning tree ports by vlan

VLAN Blocking Listening Learning Forwarding STP Active

----- -------- --------- -------- ---------- ----------

1 0 0 0 36 36

2 0 0 0 55 55

3 0 0 0 31 31

4 0 0 0 31 31

5 0 0 0 31 31

6 0 0 0 31 31

7 0 0 0 31 31

8 0 0 0 31 31

9 0 0 0 31 31

10 0 0 0 31 31

11 0 0 0 31 31

12 0 0 0 31 31

13 0 0 0 31 31

14 0 0 0 31 31

15 0 0 0 31 31

16 0 0 0 31 31

17 0 0 0 31 31

18 0 0 0 31 31

19 0 0 0 31 31

20 0 0 0 31 31

21 0 0 0 31 31

22 0 0 0 31 31

24 0 0 0 31 31

25 0 0 0 31 31

26 0 0 0 31 31

27 0 0 0 31 31

28 0 0 0 31 31

29 0 0 0 31 31

30 0 0 0 31 31

31 0 0 0 31 31

32 0 0 0 31 31

33 0 0 0 31 31

34 0 0 0 31 31

35 0 0 0 31 31

36 0 0 0 31 31

37 1 0 0 29 30

50 0 0 0 32 32

97 0 0 0 31 31

98 0 0 0 31 31

99 0 0 0 31 31

Blocking Listening Learning Forwarding STP Active

----- -------- --------- -------- ---------- ----------

Total 1 0 0 1268 1269