Cisco Nexus 5000 Series User manual

Cisco Nexus 5000 Series NX-OS Layer 2 Switching Configuration
Guide, Release 5.1(3)N1(1)
First Published: December 05, 2011
Last Modified: November 27, 2012
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Text Part Number: OL-25842-01

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CONTENTS
Preface Preface xvii
Audience xvii
Document Conventions xvii
Documentation Feedback xix
Obtaining Documentation and Submitting a Service Request xix
CHAPTER 1 New and Changed Information 1
New and Changed Information for this Release 1
CHAPTER 2 Overview 3
Layer 2 Ethernet Switching Overview 3
VLANs 3
Private VLANs 4
Spanning Tree 4
STP Overview 4
Rapid PVST+ 5
MST 5
STP Extensions 5
CHAPTER 3 Configuring Ethernet Interfaces 7
Information About Ethernet Interfaces 7
Interface Command 7
Information About Unified Ports 8
Guidelines and Limitations for Unified Ports 8
Unidirectional Link Detection Parameter 8
Default UDLD Configuration 9
UDLD Aggressive and Nonaggressive Modes 10
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Interface Speed 10
Cisco Discovery Protocol 10
Default CDP Configuration 10
Error-Disabled State 11
About Port Profiles 11
Guidelines and Limitations for Port Profiles 12
Debounce Timer Parameters 13
MTU Configuration 13
Configuring Ethernet Interfaces 13
Configuring a Layer 3 Interface on a Cisco Nexus Device 13
Configuring Unified Ports 14
Configuring the UDLD Mode 15
Configuring Interface Speed 17
Disabling Link Negotiation 17
Configuring the CDP Characteristics 18
Enabling or Disabling CDP 19
Enabling the Error-Disabled Detection 20
Enabling the Error-Disabled Recovery 21
Configuring the Error-Disabled Recovery Interval 22
Port Profiles 23
Creating a Port Profile 23
Modifying a Port Profile 24
Enabling a Specific Port Profile 26
Inheriting a Port Profile 27
Removing an Inherited Port Profile 28
Assigning a Port Profile to a Range of Interfaces 30
Removing a Port Profile from a Range of Interfaces 30
Configuration Examples for Port Profiles 31
Configuring the Debounce Timer 32
Configuring the Description Parameter 33
Disabling and Restarting Ethernet Interfaces 34
Displaying Interface Information 34
Default Physical Ethernet Settings 37
CHAPTER 4 Configuring VLANs 39
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Information About VLANs 39
Understanding VLANs 39
Understanding VLAN Ranges 40
Creating, Deleting, and Modifying VLANs 42
About the VLAN Trunking Protocol 42
Guidelines and Limitations for VTP 43
Configuring a VLAN 43
Creating and Deleting a VLAN 43
Changing the Range of Reserved VLANs 44
Configuring a VLAN 46
Adding Ports to a VLAN 47
Configuring VTP 48
Verifying the VLAN Configuration 49
CHAPTER 5 Configuring Private VLANs 51
Information About Private VLANs 51
Primary and Secondary VLANs in Private VLANs 52
Private VLAN Ports 52
Primary, Isolated, and Community Private VLANs 53
Associating Primary and Secondary VLANs 54
Private VLAN Promiscuous Trunks 55
Private VLAN Isolated Trunks 55
Broadcast Traffic in Private VLANs 56
Private VLAN Port Isolation 56
Guidelines and Limitations for Private VLANs 56
Configuring a Private VLAN 57
Enabling Private VLANs 57
Configuring a VLAN as a Private VLAN 57
Associating Secondary VLANs with a Primary Private VLAN 58
Configuring an Interface as a Private VLAN Host Port 60
Configuring an Interface as a Private VLAN Promiscuous Port 61
Configuring a Promiscuous Trunk Port 62
Configuring an Isolated Trunk Port 63
Configuring Private VLANs on FEX Trunk Ports 64
Configuring the Allowed VLANs for PVLAN Trunking Ports 65
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Configuring Native 802.1Q VLANs on Private VLANs 66
Verifying the Private VLAN Configuration 67
CHAPTER 6 Configuring Access and Trunk Interfaces 69
Information About Access and Trunk Interfaces 69
Understanding Access and Trunk Interfaces 69
Understanding IEEE 802.1Q Encapsulation 70
Understanding Access VLANs 71
Understanding the Native VLAN ID for Trunk Ports 72
Understanding Allowed VLANs 72
Understanding Native 802.1Q VLANs 72
Configuring Access and Trunk Interfaces 73
Configuring a LAN Interface as an Ethernet Access Port 73
Configuring Access Host Ports 74
Configuring Trunk Ports 74
Configuring the Native VLAN for 802.1Q Trunking Ports 75
Configuring the Allowed VLANs for Trunking Ports 76
Configuring Native 802.1Q VLANs 77
Verifying the Interface Configuration 78
CHAPTER 7 Configuring Port Channels 79
Information About Port Channels 79
Understanding Port Channels 79
Guidelines and Limitations for Port Channel Configuration 80
Compatibility Requirements 81
Load Balancing Using Port Channels 82
Understanding LACP 85
LACP Overview 85
LACP ID Parameters 86
Channel Modes 86
LACP Marker Responders 87
LACP-Enabled and Static Port Channel Differences 88
Configuring Port Channels 88
Creating a Port Channel 88
Adding a Port to a Port Channel 89
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Configuring Load Balancing Using Port Channels 90
Configuring Hardware Hashing for Multicast Traffic 91
Enabling LACP 91
Configuring the Channel Mode for a Port 92
Configuring the LACP Fast Timer Rate 93
Configuring the LACP System Priority and System ID 94
Configuring the LACP Port Priority 95
Disabling LACP Graceful Convergence 96
Reenabling LACP Graceful Convergence 97
Verifying Port Channel Configuration 98
Verifying the Load-Balancing Outgoing Port ID 99
CHAPTER 8 Configuring Virtual Port Channels 101
Information About vPCs 101
vPC Overview 101
Terminology 103
vPC Terminology 103
Fabric Extender Terminology 103
Supported vPC Topologies 104
Cisco Nexus Device vPC Topology 104
Single Homed Fabric Extender vPC Topology 104
Dual Homed Fabric Extender vPC Topology 105
vPC Domain 105
Peer-Keepalive Link and Messages 106
Compatibility Parameters for vPC Peer Links 106
Configuration Parameters That Must Be Identical 107
Configuration Parameters That Should Be Identical 108
Graceful Type-1 Check 109
Per-VLAN Consistency Check 109
vPC Auto-Recovery 109
vPC Peer Links 109
vPC Peer Link Overview 109
vPC Number 110
vPC Interactions with Other Features 111
Configuring vPC Peer Links and Links to the Core 111
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vPC and LACP 113
vPC Peer Links and STP 113
vPC and ARP 114
CFSoE 114
vPC Peer Switch 115
Guidelines and Limitations for vPCs 115
Configuring vPCs 116
Enabling vPCs 116
Disabling vPCs 117
Creating a vPC Domain 118
Configuring a vPC Keepalive Link and Messages 118
Creating a vPC Peer Link 121
Checking the Configuration Compatibility 122
Enabling vPC Auto-Recovery 123
Configuring the Restore Time Delay 124
Excluding VLAN Interfaces from Shutting Down a vPC Peer Link Fails 125
Configuring the VRF Name 126
Binding a VRF Instance to a vPC 126
Enabling Layer 3 Forwarding to the Gateway MAC Address of the vPC 127
Suspending Orphan Ports on a Secondary Switch in a vPC Topology 128
Creating an EtherChannel Host Interface 129
Moving Other Port Channels into a vPC 130
Manually Configuring a vPC Domain MAC Address 131
Manually Configuring the System Priority 132
Manually Configuring a vPC Peer Switch Role 133
Configuring the vPC Peer Switch 134
Configuring a Pure vPC Peer Switch Topology 134
Configuring a Hybrid vPC Peer Switch Topology 136
Verifying the vPC Configuration 138
Viewing the Graceful Type-1 Check Status 138
Viewing a Global Type-1 Inconsistency 139
Viewing an Interface-Specific Type-1 Inconsistency 140
Viewing a Per-VLAN Consistency Status 141
vPC Example Configurations 143
Dual Homed Fabric Extender vPC Configuration Example 143
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Single Homed Fabric Extender vPC Configuration Example 145
vPC Default Settings 147
CHAPTER 9 Configuring Enhanced Virtual Port Channels 149
Information About Enhanced vPCs 150
Enhanced Virtual Port Channels Overview 150
Supported Platforms and Topologies 150
Enhanced vPC Scalability 151
Enhanced vPC Failure Response 151
Licensing Requirements for Enhanced vPC 152
Configuring Enhanced vPCs 152
Overview of Configuration Steps for Enhanced vPC 152
Verifying Enhanced vPCs 153
Verifying the Enhanced vPC Configuration 153
Verifying the Consistency of Port Channel Numbers 154
Verifying Common Port Channel Members 155
Verifying Interface Level Consistency for Enhanced vPCs 156
Enhanced vPC Example Configuration 157
CHAPTER 10 Configuring Rapid PVST+ 161
Information About Rapid PVST+ 161
Understanding STP 161
STP Overview 161
Understanding How a Topology is Created 162
Understanding the Bridge ID 162
Bridge Priority Value 162
Extended System ID 163
STP MAC Address Allocation 163
Understanding BPDUs 164
Election of the Root Bridge 165
Creating the Spanning Tree Topology 165
Understanding Rapid PVST+ 166
Rapid PVST+ Overview 166
Rapid PVST+ BPDUs 167
Proposal and Agreement Handshake 168
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Protocol Timers 169
Port Roles 169
Port States 170
Rapid PVST+ Port State Overview 170
Blocking State 171
Learning State 171
Forwarding State 171
Disabled State 172
Summary of Port States 172
Synchronization of Port Roles 172
Processing Superior BPDU Information 173
Processing Inferior BPDU Information 174
Spanning-Tree Dispute Mechanism 174
Port Cost 174
Port Priority 175
Rapid PVST+ and IEEE 802.1Q Trunks 175
Rapid PVST+ Interoperation with Legacy 802.1D STP 175
Rapid PVST+ Interoperation with 802.1s MST 176
Configuring Rapid PVST+ 176
Enabling Rapid PVST+ 176
Enabling Rapid PVST+ per VLAN 177
Configuring the Root Bridge ID 178
Configuring a Secondary Root Bridge 179
Configuring the Rapid PVST+ Port Priority 180
Configuring the Rapid PVST+ Path-Cost Method and Port Cost 181
Configuring the Rapid PVST+ Bridge Priority of a VLAN 182
Configuring the Rapid PVST+ Hello Time for a VLAN 183
Configuring the Rapid PVST+ Forward Delay Time for a VLAN 183
Configuring the Rapid PVST+ Maximum Age Time for a VLAN 184
Specifying the Link Type 185
Restarting the Protocol 185
Verifying the Rapid PVST+ Configuration 186
CHAPTER 11 Configuring Multiple Spanning Tree 187
Information About MST 187
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