Cisco Catalyst 3750 Software Configuration Guide

CHAPTER
14-1
Catalyst 3750 Metro Switch Software Configuration Guide
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14
Configuring STP
This chapter describes how to configure the Spanning Tree Protocol (STP) on port-based VLANs on the
Catalyst 3750 Metro switch. The switch uses the per-VLAN spanning-tree plus (PVST+) protocol based
on the IEEE 802.1D standard and Cisco proprietary extensions, or it can use the rapid per-VLAN
spanning-tree plus (rapid-PVST+) protocol based on the IEEE 802.1w standard.
For information about the Multiple Spanning Tree Protocol (MSTP) and how to map multiple VLANs
to the same spanning-tree instance, see Chapter 15, “Configuring MSTP.” For information about other
spanning-tree features such as Port Fast, UplinkFast, root guard, and so forth, see Chapter 16,
“Configuring Optional Spanning-Tree Features.”
Note For complete syntax and usage information for the commands used in this chapter, refer to the command
reference for this release.
This chapter consists of these sections:
• Understanding Spanning-Tree Features, page 14-1
• Configuring Spanning-Tree Features, page 14-11
• Displaying the Spanning-Tree Status, page 14-22
Understanding Spanning-Tree Features
These sections describe how basic spanning-tree features work:
• STP Overview, page 14-2
• Spanning-Tree Topology and BPDUs, page 14-3
• Bridge ID, Switch Priority, and Extended System ID, page 14-4
• Spanning-Tree Interface States, page 14-4
• How a Switch or Port Becomes the Root Switch or Root Port, page 14-7
• Spanning Tree and Redundant Connectivity, page 14-8
• Spanning-Tree Address Management, page 14-8
• Accelerated Aging to Retain Connectivity, page 14-8
• Spanning-Tree Modes and Protocols, page 14-9
• Supported Spanning-Tree Instances, page 14-10

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