Specifications

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Cisco MWR 2941 Mobile Wireless Edge Router Release 3.5 Software Configuration Guide, Cisco IOS Release 15.1(3)MR
OL-26895-01
Chapter 9 Configuring STP
Configuring Spanning-Tree Features
To disable spanning tree on an ENI, enter the no spanning-tree interface command.
Changing the Spanning-Tree Mode
The router supports two spanning-tree modes: PVST+ or MSTP. By default, the router runs the PVST+
protocol on all NNIs and ENIs on which spanning tree is enabled.
Beginning in privileged EXEC mode, follow these steps to change the spanning-tree mode. If you want
to enable a mode that is different from the default mode, this procedure is required.
Step 4
spanning-tree Enable spanning tree on the interface. The interface will belong to the
switch spanning tree instance along with NNIs in the VLAN.
Note This command is visible only on ENIs.
Step 5
end Return to privileged EXEC mode.
Step 6
show spanning-tree interface
interface-id
Verify your entries.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
spanning-tree mode {pvst | mst } Configure a spanning-tree mode on STP ports on the switch.
• Select pvst to enable PVST+.
• Select mst to enable MSTP (and RSTP). For more configuration
steps, see Chapter 10, “Configuring MSTP.”
The default setting is PVST+.
Step 3
interface interface-id (Recommended only for rapid-PVST+ mode) Specify an STP port to
configure, and enter interface configuration mode. Valid interfaces
include physical NNIs or ENIs with spanning tree enabled, VLANs, and
NNIs. The VLAN ID range is 1 to 4094. The port-channel range is 1 to
48.
Note If the interface is a VLAN, only ports with spanning tree
enabled in the VLAN will run spanning tree.
Step 4
spanning-tree link-type point-to-point (Recommended only for rapid-PVST+ mode) Specify that the link type
for this port is point-to-point.
If you connect this port to a remote port through a point-to-point link
and the local port becomes a designated port, the router negotiates with
the remote port and rapidly changes the local port to the forwarding
state.
Step 5
end Return to privileged EXEC mode.
Step 6
clear spanning-tree detected-protocols (Recommended only for rapid-PVST+ mode) If any port on the router
running spanning tree is connected to a port on a legacy IEEE 802.1D
switch, restart the protocol migration process on the entire router.