Cisco ME 3600X, Command Reference Manual

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Cisco ME 3800X and ME 3600X Switch Command Reference
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Chapter 2 Cisco ME 3800X and ME 3600X Switch Cisco IOS Commands
clear spanning-tree counters
clear spanning-tree counters
To clear the spanning-tree counters or to restart the protocol migration processor on all spanning-tree
interfaces or on the specified interface, use the
clear spanning-tree counters command in privileged
EXEC mode.
clear spanning-tree {counters [ interface interface-id ] | detected-protocols [ interface
interface-id ]}
Syntax Description
Defaults
No default is defined.
Command Modes
Privileged EXEC
Command History
Usage Guidelines If the interface-id is not specified, spanning-tree counters are cleared for all STP ports or the protocol
migration is restarted on all STP ports.
A switch running the rapid per-VLAN spanning-tree plus (rapid-PVST+) protocol or the Multiple
Spanning Tree Protocol (MSTP) supports a built-in protocol migration mechanism that enables it to
interoperate with legacy IEEE 802.1D switches. If a rapid-PVST+ switch or an MSTP switch receives a
legacy IEEE 802.1D configuration bridge protocol data unit (BPDU) with the protocol version set to 0,
it sends only IEEE 802.1D BPDUs on that port. A multiple spanning-tree (MST) switch can also detect
that a port is at the boundary of a region when it receives a legacy BPDU, an MST BPDU (Version 3)
associated with a different region, or a rapid spanning-tree (RST) BPDU (Version 2).
However, the switch does not automatically revert to the rapid-PVST+ or the MSTP mode if it no longer
receives IEEE 802.1D BPDUs. It cannot learn whether the legacy switch has been removed from the link
unless the legacy switch is the designated switch. Use the
clear spanning-tree detected-protocols
command in this situation.
Examples This example shows how to clear spanning-tree counters for all STP ports:
Switch# clear spanning-tree counters
counters Clears the spanning-tree counters.
detected-protocols Restarts the protocol migration process (force the renegotiation with
neighboring switches).
interface interface-id (Optional) Clears all spanning-tree counters or restart the protocol migration
process on the specified interface. Valid interfaces include physical
interfaces, VLANs, and spanning-tree port channels. The VLAN range is 1
to 4094. The port-channel range is 1 to 26.
Release Modification
12.2(52)EY This command was introduced.