Cisco 7604 User Manual

19-21
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 19 Configuring Standard-Compliant IEEE MST
Configuring MST
To configure a router as the secondary root bridge, perform this task:
To return the router to its default setting, use the no spanning-tree mst instance_id root global
configuration command.
Configuring Port Priority
If a loop occurs, MST uses the port priority when selecting an interface to put into the forwarding state.
You can assign higher priority values (lower numerical values) to interfaces that you want selected first
and lower priority values (higher numerical values) that you want selected last. If all interfaces have the
same priority value, MST puts the interface with the lowest interface number in the forwarding state and
blocks the other interfaces.
To configure the MST port priority of an interface, perform this task:
Command Purpose
Step 1
Router# configure terminal
Enters global configuration mode.
Step 2
Router(config)# spanning-tree mst instance_id
root secondary
[diameter net_diameter [hello-time
seconds ]]
(Optional) Configures a router as the secondary root
bridge.
• For instance_id, you can specify a single instance, a
range of instances separated by a hyphen, or a series
of instances separated by a comma. The range is 0 to
4094.
• (Optional) For diameter net_diameter, specify the
maximum number of routers between any two end
stations. The range is 2 to 7. This keyword is
available only for MST instance 0.
• (Optional) For hello-time seconds, specify the
interval in seconds between the generation of
configuration messages by the root bridge. The range
is 1 to 10 seconds; the default is 2 seconds.
Use the same network diameter and hello-time values
that you used when configuring the primary root bridge.
See the “Configuring the Root Bridge” section on
page 19-19.
Step 3
Router(config)# end
Returns to privileged EXEC mode.
Step 4
Router# show spanning-tree mst instance_id
Verifies your entries.
Step 5
Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
Command Purpose
Step 1
Router# configure terminal
Enters global configuration mode.
Step 2
Router(config)# interface {{ type
1
slot/port } |
{port-channel
number }}
(Optional) Specifies an interface to configure, and enters
interface configuration mode.

Cisco 7604 Specifications

General

Brand	Cisco
Model	7604
Category	Network Router
Language	English