Cisco Nexus 3000 series User manual

Cisco Nexus 3000 Series NX-OS Layer 2 Switching Configuration
Guide, Release 5.0(3)U1(1)

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CONTENTS
Preface Preface xi
Audience xi
Document Organization xi
Document Conventions xii
Related Documentation for Nexus 3000 Series NX-OS Software xii
Obtaining Documentation and Submitting a Service Request xiii
CHAPTER 1 Overview 1
VLANs 1
Private VLANs 1
Spanning Tree 2
STP Overview 2
Rapid PVST+ 2
MST 2
STP Extensions 3
CHAPTER 2 Configuring Ethernet Interfaces 5
Information About Ethernet Interfaces 5
About the Interface Command 5
About the Unidirectional Link Detection Parameter 6
Default UDLD Configuration 7
UDLD Aggressive and Nonaggressive Modes 7
About Interface Speed 8
About the Cisco Discovery Protocol 8
Default CDP Configuration 8
About the Error-Disabled State 9
About Port Profiles 9
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Guidelines and Limitations for Port Profiles 9
About the Debounce Timer Parameters 9
About MTU Configuration 9
Configuring Ethernet Interfaces 10
Configuring the UDLD Mode 10
Configuring Interface Speed 11
Configuring the CDP Characteristics 12
Enabling or Disabling CDP 13
Enabling the Error-Disabled Detection 14
Enabling the Error-Disabled Recovery 15
Configuring the Error-Disabled Recovery Interval 16
Configuring the Debounce Timer 17
Configuring the Description Parameter 17
Disabling and Restarting Ethernet Interfaces 18
Displaying Interface Information 18
Default Physical Ethernet Settings 20
CHAPTER 3 Configuring VLANs 23
Information About VLANs 23
Understanding VLANs 23
Understanding VLAN Ranges 24
Creating, Deleting, and Modifying VLANs 25
About the VLAN Trunking Protocol 26
Guidelines and Limitations for VTP 26
Configuring a VLAN 27
Creating and Deleting a VLAN 27
Entering the VLAN Submode and Configuring the VLAN 28
Configuring VTP 29
Adding Ports to a VLAN 30
Verifying VLAN Configuration 31
CHAPTER 4 Configuring Private VLANs 33
Information About Private VLANs 33
Primary and Secondary VLANs in Private VLANs 34
Private VLAN Ports 34
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Primary, Isolated, and Community Private VLANs 35
Associating Primary and Secondary VLANs 36
Private VLAN Promiscuous Trunks 37
Private VLAN Isolated Trunks 37
Broadcast Traffic in Private VLANs 37
Private VLAN Port Isolation 37
Guidelines and Limitations for Private VLANs 38
Configuring a Private VLAN 38
Enabling Private VLANs 38
Configuring a VLAN as a Private VLAN 39
Associating Secondary VLANs with a Primary Private VLAN 40
Configuring an Interface as a Private VLAN Host Port 41
Configuring an Interface as a Private VLAN Promiscuous Port 42
Configuring a Promiscuous Trunk Port 43
Configuring an Isolated Trunk Port 43
Configuring the Allowed VLANs for PVLAN Trunking Ports 43
Configuring Native 802.1Q VLANs on Private VLANs 44
Verifying Private VLAN Configuration 44
CHAPTER 5 Configuring Access and Trunk Interfaces 45
Information About Access and Trunk Interfaces 45
Understanding Access and Trunk Interfaces 45
Understanding IEEE 802.1Q Encapsulation 46
Understanding Access VLANs 46
Understanding the Native VLAN ID for Trunk Ports 47
Understanding Allowed VLANs 47
Understanding Native 802.1Q VLANs 47
Configuring Access and Trunk Interfaces 48
Configuring a LAN Interface as an Ethernet Access Port 48
Configuring Access Host Ports 49
Configuring Trunk Ports 50
Configuring the Native VLAN for 802.1Q Trunking Ports 50
Configuring the Allowed VLANs for Trunking Ports 51
Configuring Native 802.1Q VLANs 52
Verifying Interface Configuration 53
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CHAPTER 6 Configuring EtherChannels 55
Information About EtherChannels 55
Understanding EtherChannels 55
Compatibility Requirements 56
Load Balancing Using EtherChannels 58
Understanding LACP 59
LACP Overview 59
LACP ID Parameters 60
Channel Modes 60
LACP Marker Responders 61
LACP-Enabled and Static EtherChannels Differences 62
Configuring EtherChannels 62
Creating an EtherChannel 62
Adding a Port to an EtherChannel 63
Configuring Load Balancing Using Port Channels 64
Configuring Hardware Hashing for Multicast Traffic 65
Enabling LACP 66
Configuring the Channel Mode for a Port 66
Configuring the LACP Fast Timer Rate 68
Configuring the LACP System Priority and System ID 69
Configuring the LACP Port Priority 69
Verifying EtherChannel Configuration 70
Verifying the Load-Balancing Outgoing Port ID 71
CHAPTER 7 Configuring Rapid PVST+ 73
Information About Rapid PVST+ 73
Understanding STP 74
STP Overview 74
Understanding How a Topology is Created 74
Understanding the Bridge ID 74
Bridge Priority Value 75
Extended System ID 75
STP MAC Address Allocation 75
Understanding BPDUs 76
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Election of the Root Bridge 77
Creating the Spanning Tree Topology 77
Understanding Rapid PVST+ 78
Rapid PVST+ Overview 78
Rapid PVST+ BPDUs 80
Proposal and Agreement Handshake 81
Protocol Timers 82
Port Roles 82
Port States 83
Rapid PVST+ Port State Overview 83
Blocking State 84
Learning State 84
Forwarding State 85
Disabled State 85
Summary of Port States 85
Synchronization of Port Roles 86
Processing Superior BPDU Information 86
Processing Inferior BPDU Information 87
Spanning-Tree Dispute Mechanism 87
Port Cost 87
Port Priority 88
Rapid PVST+ and IEEE 802.1Q Trunks 88
Rapid PVST+ Interoperation with Legacy 802.1D STP 89
Rapid PVST+ Interoperation with 802.1s MST 89
Configuring Rapid PVST+ 89
Enabling Rapid PVST+ 90
Enabling Rapid PVST+ per VLAN 90
Configuring the Root Bridge ID 91
Configuring a Secondary Root Bridge 93
Configuring the Rapid PVST+ Port Priority 93
Configuring the Rapid PVST+ Pathcost Method and Port Cost 94
Configuring the Rapid PVST+ Bridge Priority of a VLAN 95
Configuring the Rapid PVST+ Hello Time for a VLAN 96
Configuring the Rapid PVST+ Forward Delay Time for a VLAN 97
Configuring the Rapid PVST+ Maximum Age Time for a VLAN 97
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Specifying the Link Type 98
Restarting the Protocol 99
Verifying Rapid PVST+ Configurations 99
CHAPTER 8 Configuring Multiple Spanning Tree 101
Information About MST 101
MST Overview 101
MST Regions 102
MST BPDUs 102
MST Configuration Information 103
IST, CIST, and CST 104
IST, CIST, and CST Overview 104
Spanning Tree Operation Within an MST Region 104
Spanning Tree Operations Between MST Regions 105
MST Terminology 106
Hop Count 106
Boundary Ports 106
Spanning-Tree Dispute Mechanism 107
Port Cost and Port Priority 108
Interoperability with IEEE 802.1D 108
Interoperability with Rapid PVST+: Understanding PVST Simulation 109
Configuring MST 109
MST Configuration Guidelines 109
Enabling MST 109
Entering MST Configuration Mode 110
Specifying the MST Name 111
Specifying the MST Configuration Revision Number 112
Specifying the Configuration on an MST Region 113
Mapping and Unmapping VLANs to MST Instances 114
Mapping Secondary VLANs to Same MSTI as Primary VLANs for Private VLANs 115
Configuring the Root Bridge 116
Configuring a Secondary Root Bridge 117
Configuring the Port Priority 118
Configuring the Port Cost 119
Configuring the Switch Priority 120
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Configuring the Hello Time 121
Configuring the Forwarding-Delay Time 122
Configuring the Maximum-Aging Time 122
Configuring the Maximum-Hop Count 123
Configuring PVST Simulation Globally 124
Configuring PVST Simulation Per Port 124
Specifying the Link Type 125
Restarting the Protocol 126
Verifying MST Configurations 127
CHAPTER 9 Configuring STP Extensions 129
About STP Extensions 129
Information About STP Extensions 129
Understanding STP Port Types 129
Spanning Tree Edge Ports 129
Spanning Tree Network Ports 130
Spanning Tree Normal Ports 130
Understanding Bridge Assurance 130
Understanding BPDU Guard 130
Understanding BPDU Filtering 131
Understanding Loop Guard 132
Understanding Root Guard 132
Configuring STP Extensions 133
STP Extensions Configuration Guidelines 133
Configuring Spanning Tree Port Types Globally 133
Configuring Spanning Tree Edge Ports on Specified Interfaces 134
Configuring Spanning Tree Network Ports on Specified Interfaces 135
Enabling BPDU Guard Globally 137
Enabling BPDU Guard on Specified Interfaces 137
Enabling BPDU Filtering Globally 138
Enabling BPDU Filtering on Specified Interfaces 139
Enabling Loop Guard Globally 140
Enabling Loop Guard or Root Guard on Specified Interfaces 141
Verifying STP Extension Configuration 142
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CHAPTER 10 Configuring LLDP 143
Configuring Global LLDP Commands 143
Configuring Interface LLDP Commands 145
CHAPTER 11 Configuring the MAC Address Table 149
Information About MAC Addresses 149
Configuring MAC Addresses 150
Configuring a Static MAC Address 150
Configuring the Aging Time for the MAC Table 150
Clearing Dynamic Addresses from the MAC Table 151
Verifying the MAC Address Configuration 152
CHAPTER 12 Configuring IGMP Snooping 153
Information About IGMP Snooping 153
IGMPv1 and IGMPv2 154
IGMPv3 155
IGMP Snooping Querier 155
IGMP Forwarding 155
Configuring IGMP Snooping Parameters 156
Verifying IGMP Snooping Configuration 158
CHAPTER 13 Configuring Traffic Storm Control 161
Information About Traffic Storm Control 161
Traffic Storm Guidelines and Limitations 162
Configuring Traffic Storm Control 163
Verifying Traffic Storm Control Configuration 164
Traffic Storm Control Example Configuration 164
Default Traffic Storm Settings 164
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