Cisco Systems N3KC3048TP1GE MST Overview MST Regions MST BPDUs MST Configuration Information

Contents

MST Overview 89

MST Regions 90

MST BPDUs 90

MST Configuration Information 91

IST, CIST, and CST 91

IST, CIST, and CST Overview 91

Spanning Tree Operation Within an MST Region 92

Spanning Tree Operations Between MST Regions 92

MST Terminology 93

Hop Count 94

Boundary Ports 94

Spanning-Tree Dispute Mechanism 95

Port Cost and Port Priority 96

Interoperability with IEEE 802.1D 96

Interoperability with Rapid PVST+: Understanding PVST Simulation 97

Configuring MST 97

MST Configuration Guidelines 97

Enabling MST 97

Entering MST Configuration Mode 98

Specifying the MST Name 99

Specifying the MST Configuration Revision Number 100

Specifying the Configuration on an MST Region 100

Mapping and Unmapping VLANs to MST Instances 102

Mapping Secondary VLANs to Same MSTI as Primary VLANs for Private VLANs 102
Configuring the Root Bridge	103
Configuring a Secondary Root Bridge 104
Configuring the Port Priority	105
Configuring the Port Cost 106
Configuring the Switch Priority 106
Configuring the Hello Time	107
Configuring the Forwarding-Delay Time 108

Configuring the Maximum-Aging Time	108
Configuring the Maximum-Hop Count	109
Configuring PVST Simulation Globally	109
Configuring PVST Simulation Per Port	110

	Cisco Nexus 3000 NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U3(1)
viii	OL-26590-01