Spanning Tree - what version am I running?

[joeadiutori]

Hi All,

On my 2950 switch, how do I determine what version of STP I'm running?  STP or RSTP ??

I entered "sh span detail" and it says "VLAN0001 is executing the ieee compatible Spanning Tree protocol".  What version is that?  Is there a better way to figure this out?

Thank You - Joe

[Jon Marshall]

Joe

Try - "sh spanning-tree summary" and the first line should tell you which mode you are running in.

Jon

[joeadiutori]

usasgnap-tj#sh span summ
Root bridge for: none.
Extended system ID is enabled.
PortFast BPDU Guard is disabled
EtherChannel misconfiguration guard is enabled
UplinkFast is disabled
BackboneFast is disabled
Default pathcost method used is short

Name                   Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
VLAN0001                  0        0         0        1          1
VLAN0002                  0        0         0        1          1
VLAN0003                  0        0         0        1          1
VLAN0004                  0        0         0        3          3
VLAN0005                  0        0         0        4          4
VLAN0007                  0        0         0        1          1
VLAN0010                  0        0         0        1          1
VLAN0013                  0        0         0        1          1
VLAN0014                  0        0         0        1          1
VLAN0027                  0        0         0        1          1
VLAN0100                  0        0         0        1          1
VLAN0101                  0        0         0        4          4
VLAN0102                  0        0         0        2          2
VLAN0103                  0        0         0        1          1
VLAN0104                  0        0         0        1          1
VLAN0105                  0        0         0        1          1
VLAN0106                  0        0         0        2          2
VLAN0107                  0        0         0        1          1
VLAN0108                  0        0         0        1          1
VLAN0109                  0        0         0        1          1
VLAN0110                  0        0         0        1          1
VLAN0112                  0        0         0        1          1
VLAN0115                  0        0         0        1          1
VLAN0116                  0        0         0        1          1
VLAN0126                  0        0         0        1          1
VLAN0175                  0        0         0        1          1
VLAN0180                  0        0         0        1          1
VLAN0184                  0        0         0        1          1
VLAN0192                  0        0         0        1          1
VLAN0196                  0        0         0        1          1
VLAN0197                  0        0         0        1          1
VLAN0198                  0        0         0        1          1
VLAN0199                  0        0         0        1          1
VLAN0200                  0        0         0        1          1
VLAN0201                  0        0         0        1          1
VLAN0249                  0        0         0        1          1
VLAN0250                  0        0         0        1          1
VLAN0251                  0        0         0        1          1
VLAN0252                  0        0         0        1          1
VLAN0254                  0        0         0        1          1
VLAN0500                  0        0         0        1          1
VLAN0501                  0        0         0        1          1
VLAN0999                  0        0         0        1          1
---------------------- -------- --------- -------- ---------- ----------
43 vlans                  0        0         0        53         53

[joeadiutori]

usasgnap-tj#sh span

VLAN0001
  Spanning tree enabled protocol ieee
  Root ID    Priority    32768
             Address     000f.35e2.d400
             Cost        22
             Port        48 (FastEthernet0/48)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)
             Address     000a.b793.0a40
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface        Port ID                     Designated                Port ID
Name             Prio.Nbr      Cost Sts      Cost Bridge ID            Prio.Nbr
---------------- -------- --------- --- --------- -------------------- --------
Fa0/48           128.48          19 FWD         3 32768 000f.35e3.5c00  35.48

[Jon Marshall]

Joe

What IOS version do you have on the switch ?

Jon

[joeadiutori]

usasgnap-tj#sh ver
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(9)EA1, RELEASE SOF
fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Wed 24-Apr-02 06:57 by antonino
Image text-base: 0x80010000, data-base: 0x804E8000

ROM: Bootstrap program is CALHOUN boot loader

usasgnap-tj uptime is 2 weeks, 1 day, 2 hours, 22 minutes
System returned to ROM by power-on
System image file is "flash:/c2950-i6q4l2-mz.121-9.EA1.bin"

cisco WS-C2950G-48-EI (RC32300) processor (revision D0) with 20815K bytes
ory.
Processor board ID FHK0634X165
Last reset from system-reset
Running Enhanced Image
48 FastEthernet/IEEE 802.3 interface(s)
2 Gigabit Ethernet/IEEE 802.3 interface(s)

32K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address: 00:0A:B7:93:0A:40
Motherboard assembly number: 73-7409-09
Power supply part number: 34-0965-01
Motherboard serial number: FOC063404LB
Power supply serial number: DAB06326MWX
Model revision number: D0
Motherboard revision number: A0
Model number: WS-C2950G-48-EI
System serial number: FHK0634X165
Configuration register is 0xF

[Jon Marshall · Accepted solution]

Okay i was using a later IOS version for your switch. For your version it looks like only PVST and MST are supported whereas the version i was looking at also support Rapid-PVST.

For your version the default is PVST so unless you have a line in your config saying -

spanning-tree mode mst

then you are running PVST.

Jon

[joeadiutori]

Jon,

It appears I am running the default (PVST).

Thank You - Joe