Cisco Catalyst 3550

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Catalyst 3550 Multilayer Switch Command Reference
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Chapter 2 Catalyst 3550 Switch Cisco IOS Commands
spanning-tree mst max-hops
spanning-tree mst max-hops
Use the spanning-tree mst max-hops global configuration command to set the number of hops in a
region before the bridge protocol data unit (BPDU) is discarded and the information held for a port is
aged. Use the no form of this command to return to the default setting.
spanning-tree mst max-hops hop-count
no spanning-tree mst max-hops
Syntax Description
Defaults The default is 20 hops.
Command Modes Global configuration
Command History
Usage Guidelines The root switch of the instance always sends a BPDU (or M-record) with a cost of 0 and the hop count
set to the maximum value. When a switch receives this BPDU, it decrements the received remaining hop
count by one and propagates the decremented count as the remaining hop count in the generated
M-records. A switch discards the BPDU and ages the information held for the port when the count
reaches 0.
Changing the spanning-tree mst max-hops command affects all spanning-tree instances.
Examples This example shows how to set the spanning-tree max-hops to 10 for all MST instances:
Switch(config)# spanning-tree mst max-hops 10
You can verify your settings by entering the show spanning-tree mst privileged EXEC command.
Related Commands
hop-count Number of hops in a region before the BPDU is discarded. The range is 1 to 255 hops.
Release Modification
12.1(9)EA1 This command was introduced.
12.2(25)SEC The hop-count range changed to 1 to 255.
Command Description
show spanning-tree mst Displays multiple spanning-tree (MST) information.
spanning-tree mst forward-time Sets the forward-delay time for all MST instances.
spanning-tree mst hello-time Sets the interval between hello BPDUs sent by root switch
configuration messages.
spanning-tree mst max-age Sets the interval between messages that the spanning tree
receives from the root switch.