User manual

Configuring Spanning Tree
Page 17-32
Manual Mode
Allows you to manually set the state for each port (forwarding or blocking) or defer the port’s
state configuration to the spanning tree protocol, which will either be IEEE 802.1d or IBM.
This column is especially helpful if you are using the IBM Spanning Tree protocol with non-
Token Ring (e.g., FDDI or Ethernet) ports that do not support this IBM Spanning Tree. In this
situation you can manually set those ports to a forwarding (or blocking) state since the IBM
Spanning Tree protocol will not be able to control these ports. The possible settings for this
column are:
f The port is in forwarding state and remains so unless you change it.
b The port is in blocking state and remains so unless you change it.
n The state of the port is determined by the IEEE 802.1d Spanning Tree
protocol. This option is not recommended because it means this Group
will have a hybrid spanning tree algorithm that mixes the IEEE 802.1d
and IBM Spanning Tree.
Displaying Spanning Tree Port Parameters
The stps command allows you to view the current spanning tree port parameters. To view the
port parameters, enter the stps command as shown:
stps <groupNumber>
where <groupNumber> is the number of the group in the switch for which you want to view
spanning tree port parameters. For example, to view parameters for Group 1, you would
enter:
stps 1
A screen similar to the following is shown:
Spanning Tree Port Summary for Group 1 (Default GROUP (#1))
Slot Service Path Desig Des Rt Swt Fw Root Bridge ID
Intf Inst Pri State MAC Cost Cost Pt Pt Pt Tx Desig BridgeID
----- ---------- ----- ----------- ----------- ------ ------- ------ ------ ------ ---- --------------------------------
3/1 Brg/ 1 128 FORWD C473C4 10 10 No Yes No 0 0010-0020DA:81D5B0
8000-0020DA:0C41E1
As a variation to this command, you can enter stps at the system prompt without specifying a
group number. This will allow you to view the port parameters on the currently selected
group. For information on how to select a group, see Selecting a Default Group on page 17-7.