Spanning-tree

[ssweehinlew]

I just want to proof my concept is correct. if the blocking state is showing "0" based on output below, that means there is no looping in the network which is blocked by spanning-tree protocol? 

switch#show spanning-tree summary 
Switch is in pvst mode
Root bridge for: VLAN0001-VLAN0002, VLAN0025, VLAN0037
Extended system ID           is enabled
Portfast Default             is disabled
PortFast BPDU Guard Default  is disabled
Portfast BPDU Filter Default is disabled
Loopguard Default            is disabled
EtherChannel misconfig guard is enabled
UplinkFast                   is disabled
BackboneFast                 is disabled
Configured Pathcost method used is short

Name                   Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
VLAN0001                     0         0        0         11         11
VLAN0002                     0         0        0          9          9
VLAN0025                     0         0        0          8          8
VLAN0037                     0         0        0          8          8
---------------------- -------- --------- -------- ---------- ----------
4 vlans                      0         0        0         36         36

switch#sh spanning-tree interface vlan 37
no spanning tree info available for Vlan30 

switch#sh spanning-tree interface vlan 25
no spanning tree info available for Vlan15 

switch#sh spanning-tree interface vlan 2 
no spanning tree info available for Vlan2 

[Jon Marshall]

if the blocking state is showing "0" based on output below, that means there is no looping in the network which is blocked by spanning-tree protocol?

It means there are no ports blocking on this switch but it doesn't tell you anything about the rest of your network.

The output above is from the root switch so all it's ports will be forwarding (unless you connect ports to each other) but there may be other switches in your network that have blocked ports.

It depends on your network topology ie. do you have other switches and do you have redundant links between switches ?

If so then you will find some ports blocked on some switches but this isn't a problem, that's what STP is meant to do.

If this is the only switch in your network then yes you can safely say there are no redundant paths in the network that have to blocked.

Jon