Cisco Catalyst 3750 User Manual

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Catalyst 3750 Switch Command Reference
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Chapter 2 Catalyst 3750 Switch Cisco IOS Commands
clear spanning-tree detected-protocols
clear spanning-tree detected-protocols
Use the clear spanning-tree detected-protocols privileged EXEC command to restart the protocol
migration process (force the renegotiation with neighboring switches) on all interfaces or on the
specified interface.
clear spanning-tree detected-protocols [interface interface-id]
Syntax Description
Defaults No default is defined.
Command Modes Privileged EXEC
Command History
Usage Guidelines 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 because 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 restart the protocol migration process on a port:
Switch# clear spanning-tree detected-protocols interface gigabitethernet2/0/1
Related Commands
interface interface-id (Optional) Restart the protocol migration process on the specified interface.
Valid interfaces include physical ports, VLANs, and port channels. The
VLAN range is 1 to 4094. The port-channel range is 1 to 48.
Release Modification
12.1(14)EA1 This command was introduced.
Command Description
show spanning-tree Displays spanning-tree state information.
spanning-tree link-type Overrides the default link-type setting and enables rapid spanning-tree
changes to the forwarding state.

Cisco Catalyst 3750 Specifications

General

Device Type	Switch
Switching Capacity	32 Gbps
Forwarding Rate	38.7 Mpps
Stacking Bandwidth	32 Gbps
RAM	128 MB
Jumbo Frame Support	Yes
Switch Type	Managed
Model	Catalyst 3750 Series
Uplink Interfaces	SFP
Form Factor	Rack-mountable
MAC Address Table Size	12, 000 entries
Routing Protocol	RIP, OSPF, EIGRP
Remote Management Protocol	SNMP, Telnet, HTTP
Features	Layer 3 switching, Layer 2 switching, auto-negotiation, BOOTP support, ARP support, VLAN support, auto-uplink (auto MDI/MDI-X), IGMP snooping, traffic shaping, MAC address filtering, Quality of Service (QoS), Jumbo Frames support, MLD snooping, Dynamic ARP Inspection (DAI), Cisco EnergyWise technology
Power over Ethernet (PoE)	PoE
Operating Temperature	-5 - 45 °C
Operating Humidity	10% to 85% non-condensing