Page 1 Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x First Published: 2010-03-05 Last Modified: 2017-11-29 Americas Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 527-0883...
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Page 3: Table Of Contents
Configuring Layer 2 Switching C H A P T E R 3 Finding Feature Information Information About Layer 2 Switching Layer 2 Ethernet Switching Overview Switching Frames Between Segments Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 4 Virtualization Support for VLANs Licensing Requirements for VLANs Prerequisites for Configuring VLANs Guidelines and Limitations for Configuring VLANs Default Settings for VLANs Configuring a VLAN Creating and Deleting a VLAN Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 5 Information About Private VLANs Private VLAN Overview Primary and Secondary VLANs in Private VLANs Private VLAN Ports Primary, Isolated, and Community Private VLANs Associating Primary and Secondary VLANs Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 6 Verifying PVLAN (Isolated) Configurations on FEX HIF Verifying the Private VLAN Configuration Displaying and Clearing Private VLAN Statistics Configuration Examples for Private VLANs Additional References for Private VLANs Feature History for Configuring Private VLANs Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 7 Detecting Unidirectional Link Failure:Rapid PVST+ Port Cost Port Priority Rapid PVST+ and IEEE 802.1Q Trunks Rapid PVST+ Interoperation with Legacy 802.1D STP Rapid PVST+ Interoperation with 802.1s MST Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 8 C H A P T E R 8 Finding Feature Information Information About MST MST Overview MST Regions MST BPDUs MST Configuration Information IST, CIST, and CST IST, CIST, and CST Overview Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x viii...
Page 9 Configuring the MST Maximum-Hop Count Configuring an Interface to Proactively Send Prestandard MSTP Messages—CLI Version Specifying the Link Type for MST—CLI Version Reinitializing the Protocol for MST Verifying the MST Configuration Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 10 Enabling BPDU Filtering on Specified Interfaces Enabling Loop Guard Globally Enabling Loop Guard or Root Guard on Specified Interfaces Configuring PVST Simulation Globally—CLI Version Configuring PVST Simulation Per Port Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 11 Feature History for Configuring STP Extensions—CLI version Configuration Limits for Layer 2 Switching A P P E N D I X A Configuration Limits for Layer 2 Switching Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 12 Contents Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 13: Preface
Preface This preface describes the audience, organization, and conventions of the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide. It also provides information on how to obtain related documentation. This chapter includes the following sections: • Audience, page xiii •...
Page 14: Document Conventions
Braces and a vertical bar within square brackets indicate a required choice within an optional element. Indicates a variable for which you supply values, in context where italics variable cannot be used. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 15: Related Documentation For Cisco Nexus 7000 Series Nx-Os Software
Caution or loss of data. Related Documentation for Cisco Nexus 7000 Series NX-OS Software The documentation set for the Cisco Nexus 7000 Series Switches is available at the following URLs: http://www.cisco.com/c/en/us/support/switches/nexus-7000-series-switches/ tsd-products-support-series-home.html Release Notes The release notes are available at the following URL: http://www.cisco.com/c/en/us/support/switches/nexus-7000-series-switches/products-release-notes-list.html...
Page 16: Obtaining Documentation And Submitting A Service Request
What's New in Cisco Product Documentation. To receive new and revised Cisco technical content directly to your desktop, you can subscribe to the What's New in Cisco Product Documentation RSS feed. RSS feeds are a free service.
Page 17: New And Changed Information
Bug Search Tool at https://tools.cisco.com/bugsearch/ and the release notes for your software release. This book does not contain any new feature for the Cisco NX-OS Release 8.0(1). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 18 New and Changed Information New and Changed Information Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 19: Overview
C H A P T E R Overview This chapter provides an overview of the Cisco NX-OS devices that support Layer 2 features. This chapter includes the following sections: • Layer 2 Ethernet Switching Overview, page 3 • VLANs, page 3 •...
Page 20: Private Vlans
Finally, the 802.1s standard, Multiple Spanning Tree (MST), allows you to map multiple VLANs into a single spanning tree instance. Each instance runs an independent spanning tree topology. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 21: Rapid Pvst
You can use either Rapid PVST+ or MST in a given VDC; you cannot mix both in one VDC. Rapid PVST+ is the default STP protocol for Cisco NX-OS devices. Cisco NX-OS uses the extended system ID and MAC address reduction; you cannot disable these features. Note In addition, Cisco has created some proprietary features to enhance the spanning tree activities.
Page 22: Virtualization
VDC. Faults are also isolated to within the specific VDC. This VDC concept applies to all features on Cisco NX-OS, including all Layer 2 switching features. All processes work independently in each VDC. You can reuse the process identification numbers in different VDCs.
Page 23: Related Topics
• Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide • Cisco NX-OS Licensing Guide • Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide • Cisco Nexus 7000 Series NX-OS System Management Configuration Guide Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 24 Overview Related Topics Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 25: Configuring Layer 2 Switching
To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "New and Changed Information"chapter or the Feature History table in this chapter. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 26: Information About Layer 2 Switching
VLANs across an entire network. All Layer 2 switching ports maintain MAC address tables. See the Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide for complete information Note on high-availability features.
Page 27: Consistent Mac Address Tables On The Supervisor And On The Modules
See the Cisco Nexus 7000 Series NX-OS Security Command Reference for information on MAC port security. Consistent MAC Address Tables on the Supervisor and on the Modules Optimally, all the MAC address tables on each module exactly match the MAC address table on the supervisor.
Page 28: High Availability For Switching
Release 4.2(1), if you have configured static MAC addresses on Layer 3 interfaces, you must unconfigure those ports in order to downgrade the software. See the Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide for complete information Note on high availability features.
Page 29: Guidelines And Limitations For Configuring Mac Addresses
MAC address dynamically. Default Settings for Layer 2 Switching This table lists the default setting for Layer 2 switching parameters. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 30: Configuring Layer 2 Switching
Aging time 1800 seconds Configuring Layer 2 Switching If you are familiar with the Cisco IOS CLI, be aware that the Cisco NX-OS commands for this feature Note might differ from the Cisco IOS commands that you would use. Configuring a Static MAC Address You can configure MAC addresses, which are called static MAC addresses, to statically point to specified interfaces on the device.
Page 31: Configuring A Static Mac Address On A Layer 3 Interface
IGMP Snooping" of the Cisco Nexus 7000 Series NX-OS Multicast Routing Configuration Guide. You cannot configure static MAC addresses on tunnel interfaces. Note See the Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide for information on configuring Layer 3 interfaces. Before You Begin Before you configure static MAC addresses, ensure that you are in the correct VDC (or enter the switchto vdc command).
Page 32 Displays information about the Layer 3 interface. Example: switch# show interface ethernet 7/3 Step 6 (Optional) copy running-config startup-config Copies the running configuration to the startup configuration. Example: switch# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 33: Configuring The Aging Time For The Mac Address Table
918000; the default is 1800 seconds. Entering the value Example: 0 disables the MAC aging. switch(config)# mac address-table aging-time Step 3 exit Exits global configuration mode. Example: switch(config)# exit switch# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 34: Configuring Learning Mode For Vlans
Configuring Learning Mode for VLANs Beginning with NX-OS Release 6.0.1, configuring the learning mode for VLANs is supported. Based on the learning mode configured, the Cisco NX-OS software can install MAC addresses in hardware either conversationally or nonconversationally. Before You Begin Before you configure the learning mode for VLANs, ensure that you are in the correct VDC (or enter the switchto vdc command).
Page 35: Checking The Consistency Of Mac Address Tables
This example shows how to display discrepant, missing, and extra entries in the MAC address tables between the supervisor and the specified module: switch# show forwarding consistency l2 7 switch# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 36: Clearing Dynamic Addresses From The Mac Address Table
Command Purpose show mac address-table Displays information about the MAC address table. Displays information about the aging time set for the show mac address-table aging-time MAC address entries. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 37: Configuration Example For Layer 2 Switching
Displays discrepant, missing, and extra MAC addresses between the tables on the module and the supervisor. For information on the output of these commands, see the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Command Reference. Configuration Example for Layer 2 Switching...
Page 38: Feature History For Configuring Layer 2 Switching
Layer 2 consistency 4.1(2) The show forwarding consistency l2 command displays inconsistent entries on the MAC address table between the modules. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 39: Configuring Vlans
C H A P T E R Configuring VLANs This chapter describes how to configure virtual LANs (VLANs) on Cisco NX-OS devices. This chapter includes the following sections: • Finding Feature Information, page 23 • Information About VLANs, page 24 •...
Page 40: Information About Vlans
This table describes the VLAN ranges. Table 3: VLAN Ranges VLANs Numbers Range Usage Normal Cisco default. You can use this VLAN, but you cannot modify or delete it. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 41: Creating, Deleting, And Modifying Vlans
Depending on the range of the VLAN, you can configure the following parameters for VLANs (except the default VLAN): • VLAN name • VLAN state • Shutdown or not shutdown Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 42: High Availability For Vlans
For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide. However, using VDCs requires an Advanced Services license. Prerequisites for Configuring VLANs VLANs have the following prerequisites: Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 43: Guidelines And Limitations For Configuring Vlans
VLAN1 when you configure it as a switch port. VLAN ID VLAN name • Default VLAN (VLAN1)—default • All other VLANs—VLAN vlan-id VLAN state Active Enabled; Rapid PVST+ is enabled Disabled VTP version Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 44: Configuring A Vlan
4. (Optional) show vlan 5. (Optional) copy running-config startup-config DETAILED STEPS Command or Action Purpose Step 1 config t Enters global configuration mode. Example: switch# config t switch(config)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 45: Entering The Vlan Configuration Submode
Entering the VLAN Configuration Submode To configure or modify the VLAN for the following parameters, you must be in the VLAN configuration submode: • Name • State • Shut down Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 46 Copies the running configuration to the startup configuration. Example: switch(config)# copy running-config startup-config This example shows how to enter and exit VLAN configuration submode: switch# config t switch(config)# vlan 15 switch(config-vlan)# exit switch(config)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 47: Configuring A Vlan
Places you into VLAN configuration submode. If the VLAN does not exist, the system creates the specified VLAN and then enters the VLAN configuration submode. Example: switch(config)# vlan 5 switch(config-vlan)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 48 This example shows how to configure optional parameters for VLAN 5: switch# config t switch(config)# vlan 5 switch(config-vlan)# name accounting switch(config-vlan)# state active switch(config-vlan)# no shutdown switch(config-vlan)# exit switch(config)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 49: Changing The Range Of Reserved Vlans
Step 4 reload Reloads the software, and modifications to VLAN ranges become effective. For more details about this command, see the Cisco Nexus 7000 Series Example: NX-OS Fundamentals Configuration Guide, Release 6.x. switch(config)# reload Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 50: Configuring A Vlan Before Creating The Vlan
Note Configuring a VLAN Before Creating the VLAN Beginning with Cisco NX-OS Release 5.1(1), you can configure a VLAN before you create the VLAN. This procedure is used for IGMP snooping, VTP, and other configurations. The show vlan command does not display these VLANs unless you create the VLANs using the vlan Note command.
Page 51: Configuring Vlan Long-Name
If you try to enable or disable the system vlan long-name command, when it is already enabled or disabled, the system will throw error message. We recommend you view the status of the VLAN long-name knob before enabling or disabling this command. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 52 2 switch(config-vlan)# name 33Char1234567890987CiscoBangalore !ERROR: Long VLAN name is not enabled: Vlan name greater than 32 is not allowed! Switch(config-vlan)# exit Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 53: Configuring Vlan Translation On A Trunk Port
(Optional) startup-config Copies the running configuration to the startup configuration. The VLAN translation configuration does not become effective Note until the switch port becomes an operational trunk port Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 54: Verifying The Vlan Configuration
Displays VTP information. show system vlan reserved Displays system reserved VLAN range. For information on the output of these commands, see the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Command Reference. Displaying and Clearing VLAN Statistics To display VLAN configuration information, perform one of the following tasks:...
Page 55: Configuration Example For Vlans
Cisco Nexus 7000 Series NX-OS Fundamentals Configuration Guide High availability Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide System management Cisco Nexus 7000 Series NX-OS System Management Configuration Guide Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 56: Feature History For Configuring Vlans
You can configure mapping between a pair of VLANs. Configure VLAN long-name. 6.1(1) You can configure VLAN long-names. Dynamic system reserved VLAN range 5.2(1) You can change the range of the system reserve VLANs. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 57 Configure VLAN before creating the 5.1(1) You can configure a VLAN before VLAN creating the VLAN. No change 4.2(1) VLAN Trunking Protocol 4.1(2) The device now runs VTP in transparent mode. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 58 Configuring VLANs Feature History for Configuring VLANs Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 59: Configuring Vtp
Feature History table in this chapter. Information About VTP Beginning with Cisco NX-OS Release 5.1(1), VTP and VTP pruning are supported for VTP version 1 and 2. Before Release 5.1(1), only VTP transparent mode was supported. Beginning with Cisco NX-OS Release 5.1(1), you can configure VLANs without actually creating the Note VLANs.
Page 60: Vtp
(CLI). When VTP is disabled, the device does not relay any VTP protocol packets. Note Before Release 5.1(1), VTP worked only in transparent mode in the Cisco Nexus 7000 Series devices, allowing you to extend a VTP domain across the device.
Page 61: Vtp Modes
VLANs by using the CISCO-VTP-MIB without having to run VTP. On Cisco Nexus 7000 Series devices, because VTP is a conditional service, its MIB is loaded only when the corresponding feature is enabled. The CISCO-VTP-MIB does not follow this convention. It is loaded by the VLAN manager and will always return the correct values whether the VTP process is enabled or disabled.
Page 62: Vtp Pruning And Spanning Tree Protocol
VTP Version 3 has the following software restrictions: • On the Cisco Nexus 7000 Series switches, by default, the VTP version 3 is configured under the server mode. Whereas on the Cisco Nexus 9000 Series switches, by default, the VTP version 3 is configured under the transparent mode.
Page 63: Configuring Vtp
Disabling VLAN 1 from any of these ports prevents VTP from functioning properly in transparent mode. Before Cisco NX-OS Release 5.1(1), VTP worked only in transparent mode. With Cisco NX-OS Release Note 7.2(0), VTP version 3 was introduced.
Page 64 Specifies the password for the VTP administrative domain. Default hidden | secret] value is taken from vlan.dat. The following options are applicable only on an image supporting Example: VTP version 3: Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 65 Step 13 switch# show vtp interface (Optional) Displays the list of VTP-enabled interfaces. Step 14 switch# show vtp password (Optional) Displays the password for the management VTP domain. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 66: Configuring Vtp Pruning
Configuring VTP Pruning You can configure VTP pruning on the Cisco NX-OS devices. Before You Begin You must enable VTP on the device. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 67 VLAN 1 is never pruning eligible, because it is a factory-default VLAN. VLANs 1002 to 1005 are reserved for Token Ring networks. The VLANs 1006 is not pruning eligible. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 68 Configuring VTP Configuring VTP Pruning Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 69: Configuring Private Vlans Using Nx-Os
C H A P T E R Configuring Private VLANs Using NX-OS This chapter describes how to configure private VLANs on Cisco NX-OS devices. Private VLANs provide additional protection at the Layer 2 level. This chapter includes the following sections: •...
Page 70: Information About Private Vlans
The private VLAN feature allows you to partition the Layer 2 broadcast domain of a VLAN into subdomains. A subdomain is represented by a pair of private VLANs: a primary VLAN and a secondary VLAN. A private Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 71: Private Vlan Ports
• Promiscuous trunk—Beginning with Cisco NX-OS Release 5.0(2) and Cisco DCNM Release 5.1(1), on the Cisco Nexus 7000 Series devices, you can configure a promiscuous trunk port to carry traffic for multiple primary VLANs. You map the private VLAN primary VLAN and either all or selected associated VLANs to the promiscuous trunk port.
Page 72: Primary, Isolated, And Community Private Vlans
• Isolated or secondary trunk—Beginning with Cisco NX-OS Release 5.0(2) and Cisco DCNM Release 5.1(1) on the Cisco Nexus 7000 Series devices, you can configure an isolated trunk port to carry traffic for multiple isolated VLANs. Each secondary VLAN on an isolated trunk port must be associated with a different primary VLAN.
Page 73 VLAN servers from an administration workstation. Beginning with for the Nexus 7000 Series devices, you can configure private VLAN promiscuous and Note isolated trunk ports. These promiscuous and isolated trunk ports carry traffic for multiple primary and secondary VLANs as well as normal VLAN.
Page 74: Associating Primary And Secondary Vlans
VLAN or to any isolated ports. Private VLAN Port Isolation You can use private VLANs to control access to end stations as follows: Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 75: Private Vlans And Vlan Interfaces
Each VLAN must have all of its private VLAN ports for both the primary VLAN and all secondary VLANs in the same VDC. Private VLANs cannot cross VDCs. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 76: Pvlan (Isolated) On Fex Hif (Cisco Nexus 7000 Parent)
PVLAN isolated host and secondary trunk ports on FEX ports, where the parent switch is a Cisco Nexus 7000 series switch. With this feature, users can create end-to-end private VLAN (PVLAN) domain from trunk till host interface ports.
Page 77: Prerequisites For Private Vlans
VLANs match exactly so that the VLANs can properly share the same forwarding database. • For normal trunk ports, note the following: Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 78 • Because traffic in a private VLAN flows in different directions in different VLANs, you can have different VACLs for ingressing traffic and different VACLs for egressing traffic prior to configuring the mapping. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 79: Private Vlan Port Configuration
• You can configure SPAN to span both primary and secondary VLANs or to span either one if the user is interested only in ingress or egress traffic. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 80: Default Settings For Private Vlans
You must enable private VLANs on the device to have the private VLAN functionality. Note The private VLAN commands do not appear until you enable the private VLAN feature. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 81: Configuring A Vlan As A Private Vlan
You can configure a VLAN as a private VLAN. To create a private VLAN, you first create a VLAN and then configure that VLAN to be a private VLAN. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 82 {community | isolated isolated, or primary private VLAN. In a private | primary} VLAN, you must have one primary VLAN. You can have multiple community and isolated VLANs. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 83: Associating Secondary Vlans With A Primary Private Vlan
• Enter a secondary-vlan-list or enter the add keyword with a secondary-vlan-list to associate secondary VLANs with a primary VLAN. • Enter the remove keyword with a secondary-vlan-list to clear the association between secondary VLANs and a primary VLAN. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 84 5 switch(config-vlan)# Step 3 Enter one of the following commands: Option Description private-vlan association Associates the secondary VLANs {[add] secondary-vlan-list | with the primary VLAN. remove secondary-vlan-list} Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 85: Mapping Secondary Vlans To The Vlan Interface Of A Primary Vlan
Mapping Secondary VLANs to the VLAN Interface of a Primary VLAN Note See the Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide for information on assigning IP addresses to VLAN interfaces on primary VLANs of private VLANs. You map secondary VLANs to the VLAN interface of a primary VLAN. Isolated and community VLANs are both called secondary VLANs.
Page 86 Maps the secondary VLANs to the SVI {[add] secondary-vlan-list or Layer 3 interface of the primary | remove VLAN. This action allows the Layer 3 secondary-vlan-list} switching of private VLAN ingress traffic. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 87: Configuring A Layer 2 Interface As A Private Vlan Host Port
We recommend that you enable BPDU Guard on all interfaces configured as a host port. Note You then associate the host port with both the primary and secondary VLANs. Before You Begin Ensure that the private VLAN feature is enabled. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 88 VLAN can be either an isolated or community VLAN. no switchport private-vlan Removes the private VLAN host-association association from the port. Example: switch(config-if)# switchport private-vlan host-association 10 50 Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 89: Configuring A Layer 2 Interface As A Private Vlan Isolated Trunk Port
Configuring a Layer 2 Interface as a Private VLAN Isolated Trunk Port Beginning with Cisco NX-OS Release 5.0(2), you can configure a Layer 2 interface as a private VLAN isolated trunk port. These isolated trunk ports carry traffic for multiple secondary VLANs as well as normal VLANs.
Page 90 VLAN for the isolated trunk port, you must enter a value for a secondary VLAN or a normal VLAN; you cannot configure a primary VLAN as the native VLAN. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 91 Removes the private VLAN association private-vlan from the private VLAN isolated trunk association trunk port. [primary-vlan-id [secondary-vlan-id]] Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 92: Configuring A Layer 2 Interface As A Private Vlan Promiscuous Port
Ensure that you are in the correct VDC (or enter the switchto vdc command). You can repeat VLAN names and IDs in different VDCs, so you must confirm that you are working in the correct VDC. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 93 VLANs. The secondary VLAN can be either an isolated or community VLAN. no switchport private-vlan Clears the mapping from the private mapping VLAN. Example: switch(config-if)# switchport private-vlan mapping 10 50 Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 94: Configuring A Layer 2 Interface As A Private Vlan Promiscuous Trunk Port
Configuring a Layer 2 Interface as a Private VLAN Promiscuous Trunk Port Beginning with Cisco NX-OS Release 5.0(2), you can configure a Layer 2 interface as a private VLAN promiscuous trunk port and then associate that promiscuous trunk port with multiple primary VLANs. These promiscuous trunk ports carry traffic for multiple primary VLANs as well as normal VLANs.
Page 95 VLAN for the promiscuous trunk port, you must enter a value for a primary VLAN or a normal VLAN; you cannot configure a secondary VLAN as the native VLAN. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 96 VLAN that you are working with. no switchport Removes the private VLAN private-vlan promiscuous trunk mappings from the mapping trunk interface. [primary-vlan-id [secondary-vlan-id]] Example: switch(config-if)# switchport private-vlan mapping trunk 4 add 5 switch(config-if)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 97: Configuring Isolated Pvlans On Fex Hif Ports
• Ensure PVLANs are not configured or enabled on HIF FEX trunk ports. SUMMARY STEPS 1. Bring down PVLAN from coming up on the HIF FEX trunk ports. HIF ports are non-PVLANs configured ports on FEX. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 98: Configuring Pvlan On Fex Isolated Ports
Configure PVLAN association on the port. switch(config-if)# switchport private-vlan association primary-vlan-id secondary-vlan-id switch(config)# interface Ethernet100/1/13 switch(config-if)# switchport switch(config-if)# switchport mode private-vlan host switch(config-if)# switchport private-vlan host-association 550 551 Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 99: Configuring Pvlan On Trunk Secondary Port
550 switch(config-vlan)# private-vlan association 551 switch(config-vlan)# vlan 551 switch(config-vlan)# private-vlan isolated switch(config-vlan)# exit What to Do Next • (Optional) Verifying PVLAN (Isolated) Configurations on FEX HIF Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 100: Verifying Pvlan (Isolated) Configurations On Fex Hif
For detailed information about the fields in the output from these commands, see the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Command Reference. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 101: Displaying And Clearing Private Vlan Statistics
2 3 switch(config-if)# exit switch(config)# interface ethernet 1/12 switch(config-if)# switchport private-vlan mapping 2 3,4 switch(config-if)# exit switch(config)# interface vlan 2 switch(config-vlan)# private-vlan mapping 3,4 switch(config-vlan)# exit switch(config)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 102: Additional References For Private Vlans
MIBs MIBs MIBs Link To locate and download MIBs, go to the following • CISCO-PRIVATE-VLAN-MIB URL: http://www.cisco.com/public/sw-center/ netmgmt/cmtk/mibs.shtml Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 103: Feature History For Configuring Private Vlans
No change 4.2(1) – Display features enabled on 4.1(2) You can display which the device features are enabled on the device by entering the following command: • show feature Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 104 Configuring Private VLANs Using NX-OS Feature History for Configuring Private VLANs Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 105: Configuring Rapid Pvst+ Using Cisco Nx-Os
To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "New and Changed Information"chapter or the Feature History table in this chapter. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 106: Information About Rapid Pvst
Rapid PVST+ interoperates with devices that run legacy IEEE 802.1D STP. RSTP is an improvement on the original STP standard, 802.1D, which allows faster convergence. The device supports full nondisruptive upgrades for Rapid PVST+. See the Cisco Nexus 7000 Series Note NX-OS High Availability and Redundancy Guide for complete information on nondisruptive upgrades.
Page 107: How A Topology Is Created
In a switched network, the root switch is the logical center of the spanning tree topology. STP uses BPDUs to elect the root switch and root port for the switched network. The mac-address bpdu source version 2 command enables STP to use the new Cisco MAC address Note (00:26:0b:xx:xx:xx) as the source address of BPDUs generated on vPC ports.
Page 108: Extended System Id
4096. Only the following values are possible: • 0 • 4096 • 8192 • 12288 • 16384 • 20480 • 24576 Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 109: Bpdus
• The shortest distance to the root bridge is calculated for each network device based on the path cost. • A designated bridge for each LAN segment is selected. This network device is closest to the root bridge through which frames are forwarded to the root. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 110: Election Of The Root Bridge
The goal is to make the fastest link the root port. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 111: Rapid Pvst
• Edge ports—When you configure a port as an edge port on an RSTP device, the edge port immediately transitions to the forwarding state. (This immediate transition was previously a Cisco-proprietary feature named PortFast.) You should only configure ports that connect to a single end station as edge ports.
Page 112: Rapid Pvst+ Bpdus
• The role and state of the port that originates the BPDU • The proposal and agreement handshake This figure shows the use of the BPDU flags in Rapid PVST+. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 113: Proposal And Agreement Handshake
With each iteration of this handshaking process, one more switch joins the active topology. As the network converges, this proposal-agreement handshaking progresses from the root toward the leaves of the spanning tree as shown in this figure. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 114: Protocol Timers
This timer is generally not used by the protocol, but it is used when interoperating with the 802.1D spanning tree. The default is 15 seconds, and the range is from 4 to 30 seconds. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 115: Port Roles
Designated ports start in the blocking state. The port state controls the operation of the forwarding and learning processes. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 116: Rapid Pvst+ Port State Overview
When the STP algorithm places a Layer 2 LAN port in the forwarding state, the following process occurs: 1 The Layer 2 LAN port is put into the blocking state while it waits for protocol information that suggests it should go to the learning state. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 117: Blocking State
• Forwards frames received from the attached segment. • Forwards frames switched from another port for forwarding. • Incorporates the end station location information into its address database. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 118: Disabled State
An individual port on the device is synchronized if either of the following applies: • That port is in the blocking state. • It is an edge port (a port configured to be at the edge of the network). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 119: Processing Superior Bpdu Information
An inferior BPDU is a BPDU with root information (such as a higher switch ID or higher path cost) that is inferior to what is currently stored for the port. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 120: Detecting Unidirectional Link Failure:rapid Pvst
Table 12: Default Port Cost Bandwidth Short Path-Cost Method of Port Long Path-Cost Method of Port Cost Cost 10 Mbps 2,000,000 100 Mbps 200,000 1 Gigabit Ethernet 20,000 10 Gigabit Ethernet 2,000 Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 121: Port Priority
Rapid PVST+ and IEEE 802.1Q Trunks The 802.1Q trunks impose some limitations on the STP strategy for a network. In a network of Cisco network devices connected through 802.1Q trunks, the network devices maintain one instance of STP for each VLAN allowed on the trunks.
Page 122: Rapid Pvst+ Interoperation With 802.1S Mst
VDC, and each VDC runs a separate STP. Each VDC will have its own Rapid PVST+. You cannot configure Rapid PVST+ across VDCs with Cisco NX-OS software. However, you can run Rapid PVST+ in one VDC and run MST in each VDC.
Page 123: Licensing Requirements For Rapid Pvst
• You must be logged onto the device. Guidelines and Limitations for Configuring Rapid PVST+ Rapid PVST+ has the following configuration guidelines and limitations: • The maximum number of VLANs and ports is 16,000. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 124: Default Settings For Rapid Pvst
BPDUs on each VLAN allowed on the trunks. The BPDUs on the native VLAN of the trunk are sent untagged to the reserved 802.1D spanning tree multicast MAC address (01-80-C2-00-00-00). The BPDUs on all VLANs on the trunk are sent tagged to the reserved Cisco Shared Spanning Tree Protocol (SSTP) multicast MAC address (01-00-0c-cc-cc-cd).
Page 125 Maximum aging time 20 seconds. Link type Auto The default link type is determined by the duplex, as follows: • Full duplex: point-to-point link • Half duplex: shared link Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 126: Configuring Rapid Pvst
VLAN (except on those VLANS on which you disable STP). By default, Rapid PVST+ is enabled on the default VLAN and on each VLAN that you create. Guidelines for Configuring Rapid PVST+ Ensure that you are in the correct VDC (see the Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide). Enabling Rapid PVST+—CLI Version If you disable Rapid PVST+ on any VLANs, you must reenable Rapid PVRST+ on the specified VLANs.
Page 127: Disabling Or Enabling Rapid Pvst+ Per Vlan-Cli Version
You can enable or disable Rapid PVST+ on each VLAN. Rapid PVST+ is enabled by default on the default VLAN and on all VLANs that you create. Note Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 128 5 Step 3 exit Exits global configuration mode. Example: switch(config)# exit switch# Step 4 (Optional) show spanning-tree Displays the STP configuration. Example: switch# show spanning-tree Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 129: Configuring The Root Bridge Id
VLAN has a bridge priority lower than 24576, the device sets the bridge priority for the specified VLANs to 4096 less than the lowest bridge priority. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 130 2 through 4094 (except for reserved VLAN values.) The dia default is 7. The hello-time can be from 1 to 10 seconds, and the default value is 2 seconds. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 131: Configuring A Secondary Root Bridge-Cli Version
You can configure more than one device in this manner to have multiple backup root bridges. Enter the same network diameter and hello time values that you used when configuring the primary root bridge. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 132 Displays the STP configuration for the specified VLANs. Example: switch# show spanning-tree vlan 5 Step 5 copy running-config startup-config (Optional) Copies the running configuration to the startup configuration. Example: switch# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 133: Configuring The Rapid Pvst+ Bridge Priority Of A Vlan
36864, 40960, 45056, 49152, 53248, 57344, and 61440. All Example: other values are rejected. The default value is 32768. switch(config)# spanning-tree vlan 5 priority 8192 Step 3 exit Exits global configuration mode. Example: switch(config)# exit switch# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 134: Configuring The Rapid Pvst+ Port Priority-Cli Version
2. interface type slot/port 3. spanning-tree [vlan vlan-list] port-priority priority 4. exit 5. (Optional) show spanning-tree interface {ethernet slot/port | port channel channel-number} 6. (Optional) copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 135: Configuring The Rapid Pvst+ Path-Cost Method And Port Cost-Cli Version
On access ports, you can assign the port cost for each port. On trunk ports, you can assign the port cost for each VLAN; you can configure all the VLANs on a trunk with the same port cost. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 136 You configure this parameter per port on access ports Note and per VLAN on trunk ports. The default is auto, which sets the port cost on both the path-cost calculation method and the media speed. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 137: Configuring The Rapid Pvst+ Hello Time For A Vlan-Cli Version
Ensure that you are in the correct VDC (or enter the switchto vdc command). SUMMARY STEPS 1. config t 2. spanning-tree vlan vlan-range hello-time value 3. exit 4. (Optional) show spanning-tree vlan vlan_id 5. (Optional) copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 138: Configuring The Rapid Pvst+ Forward Delay Time For A Vlan-Cli Version
You can configure the forward delay time per VLAN when using Rapid PVST+. Before You Begin Ensure that you are in the correct VDC (or enter the switchto vdc command). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 139: Configuring The Rapid Pvst+ Maximum Age Time For A Vlan-Cli Version
5 forward-time 21 switch(config)# exit switch# Configuring the Rapid PVST+ Maximum Age Time for a VLAN—CLI Version You can configure the maximum age time per VLAN when using Rapid PVST+. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 140 This example shows how to configure the maximum aging time for VLAN 5 to 36 seconds: switch# config t switch(config)# spanning-tree vlan 5 max-age 36 switch(config)# exit switch# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 141: Specifying The Link Type For Rapid Pvst+-Cli Version
STP falls back to 802.1D. The default is auto, which sets switch(config-if)# spanning-tree link-type point-to-point the link type based on the duplex setting of the interface. Step 4 exit Exits interface configuration mode. Example: switch(config-if)# exit switch(config)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 142: Reinitializing The Protocol For Rapid Pvst
This example shows how to reinitialize Rapid PVST+ on the Ethernet interface on slot 2, port 8: switch# clear spanning-tree detected-protocol interface ethernet 2/8 switch# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 143: Verifying The Rapid Pvst+ Configurations
Displays information on the STP bridge. For information about the fields in the output from these commands, see the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Command Reference. Displaying and Clearing Rapid PVST+ Statistics—CLI Version...
Page 144: Additional References For Rapid Pvst+-Cli Version
Cisco Nexus 7000 Series NX-OS Release Notes Standards Standards Title IEEE 802.1Q-2006 (formerly known as IEEE 802.1s), — IEEE 802.1D-2004 (formerly known as IEEE 802.1w), IEEE 802.1D, IEEE 802.1t Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 145: Feature History For Configuring Rapid Pvst+-Cli Version
This table includes only the updates for those releases that have resulted in additions or changes to the feature. Table 14: Feature History for Configuring Rapid PVST+ Feature Name Releases Feature Information No change 4.2(1) No change 4.1(2) Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 146 Configuring Rapid PVST+ Using Cisco NX-OS Feature History for Configuring Rapid PVST+—CLI Version Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 147: Configuring Mst Using Cisco Nx-Os
C H A P T E R Configuring MST Using Cisco NX-OS This chapter describes how to configure Multiple Spanning Tree (MST) on Cisco NX-OS devices. This chapter includes the following sections: • Finding Feature Information, page 131 • Information About MST, page 132 •...
Page 148: Information About Mst
• IEEE 802.1 was defined in MST and was incorporated into IEEE 802.1Q. MST Regions To allow devices to participate in MST instances, you must consistently configure the devices with the same MST configuration information. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 149: Mst Bpdus
You can configure the three parameters of the MST configuration as follows: • Name—32-character string, null padded and null terminated, identifying the MST region • Revision number—Unsigned 16-bit number that identifies the revision of the current MST configuration Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 150: Ist, Cist, And Cst
The CIST is formed by the spanning tree algorithm running among devices that support the 802.1w, 802.1s, and 802.1D standards. The CIST inside an MST region is the same as the CST outside a region. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 151: Spanning Tree Operation Within An Mst Region
The root of the subtree is the CIST regional root. The MST region appears as a virtual device to adjacent STP devices and MST regions. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 152: Mst Terminology
The MST terminology is as follows: • The CIST root is the root bridge for the CIST, which is the unique instance that spans the whole network. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 153: Hop Count
Figure 14: MST Boundary Ports Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 154: Detecting Unidirectional Link Failure
You can configure the port costs in order to influence which port is chosen. MST always uses the long path-cost calculation method, so the range of valid values is between 1 and Note 200,000,000. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 155: Interoperability With Ieee 802.1D
MST interoperates with the Cisco prestandard MSTP whenever it receives prestandard MSTP on an MST port; no explicit configuration is necessary. In Cisco NX-OS Release 4.0(2) and later releases, you can configure specified interfaces to send prestandard MSTP messages all the time; it does not have to wait to receive a prestandard MST message to begin sending prestandard MST messages.
Page 156: Licensing Requirements For Mst
Cisco NX-OS Licensing Guide. However, using VDCs requires an Advanced Services license. Prerequisites for MST MST has the following prerequisites: • You must be logged onto the device. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 157: Guidelines And Limitations For Configuring Mst
LAN into smaller LANs interconnected by non-Layer 2 devices. The software supports full nondisruptive upgrades for MST. See the Cisco Nexus 7000 Series NX-OS Note High Availability and Redundancy Guide for complete information about nondisruptive upgrades.
Page 158: Default Settings For Mst
• 10 Mbps: 2,000,000 • 100 Mbps: 200,000 • 1 Gigabit Ethernet: 20,000 • 10 Gigabit Ethernet: 2,000 Hello time 2 seconds Forward-delay time 15 seconds Maximum-aging time 20 seconds Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 159: Configuring Mst
4. (Optional) show running-config spanning-tree all 5. (Optional) copy running-config startup-config DETAILED STEPS Command or Action Purpose Step 1 config t Enters global configuration mode. Example: switch# config t switch(config)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 160: Entering Mst Configuration Mode
MST revision number. Each command reference line creates its pending regional configuration in MST configuration mode. In Note addition, the pending region configuration starts with the current region configuration. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 161 • No VLANs are mapped to any MST instance (all VLANs are mapped to the CIST instance). • The revision number is 0. Example: switch(config)# spanning-tree mst configuration switch(config-mst)# Step 3 Enter one of the following commands: Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 162: Specifying The Mst Name
SUMMARY STEPS 1. config t 2. spanning-tree mst configuration 3. name name 4. Enter one of the following commands: 5. (Optional) show spanning-tree mst 6. (Optional) copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 163 Example: switch(config)# copy running-config startup-config This example shows how to set the name of the MST region: switch# config t switch(config)# spanning-tree mst configuration switch(config-mst)# name accounting switch(config-mst)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 164: Specifying The Mst Configuration Revision Number
Enter one of the following commands: Option Description exit Commits all the changes and exits MST configuration submode. abort Exits MST configuration submode without committing any of the changes. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 165: Specifying The Configuration On An Mst Region
3. instance instance-id vlan vlan-range 4. name name 5. revision version 6. Enter one of the following commands: 7. (Optional) show spanning-tree mst 8. (Optional) copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 166 Enter one of the following commands: Option Description exit Commits all the changes and exits MST configuration submode. abort Exits MST configuration submode without committing any of the changes. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 167: Mapping Or Unmapping A Vlan To An Mst Instance-Cli Version
When you change the VLAN-to-MSTI mapping, the system reconverges MST. Note You cannot disable an MSTI. Note Before You Begin Ensure that you are in the correct VDC (or enter the switchto vdc command). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 168 Deletes the specified instance and returns the VLANs instance-id vlan to the default MSTI, which is the CIST. vlan-range Example: switch(config-mst)# instance 3 vlan 200 Step 4 Enter one of the following commands: Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 169: Mapping Secondary Vlans To Same Msti As Primary Vlans For Private Vlans
VLAN. Enter the private-vlan synchronize command to accomplish this synchronization automatically. Before You Begin Ensure that you are in the correct VDC (or enter the switchto vdc command). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 170 Exits MST configuration submode without committing any of the changes. Example: switch(config-mst)# exit switch(config)# Step 5 show spanning-tree mst (Optional) Displays the MST configuration. Example: switch# show spanning-tree mst Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 171: Configuring The Root Bridge
Before You Begin Ensure that you are in the correct VDC (or enter the switchto vdc command). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 172 Example: switch(config)# spanning-tree mst 5 root primary Step 3 Enter one of the following commands: Option Description exit Commits all the changes and exits MST configuration submode. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 173: Configuring An Mst Secondary Root Bridge
Ensure that you are in the correct VDC (or enter the switchto vdc command). SUMMARY STEPS 1. config t 2. Enter one of the following commands: 3. exit 4. (Optional) show spanning-tree mst 5. (Optional) copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 174 Displays the MST configuration. Example: switch# show spanning-tree mst Step 5 copy running-config startup-config (Optional) Copies the running configuration to the startup configuration. Example: switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 175: Configuring The Mst Switch Priority
• For priority-value the range is from 0 to 61440 in increments of 4096; the default is 32768. A lower number indicates that the device will most likely be chosen as the root bridge. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 176: Configuring The Mst Port Priority
1. config t 2. interface {{type slot/port} | {port-channel number}} 3. spanning-tree mst instance-id port-priority priority 4. exit 5. (Optional) show spanning-tree mst 6. (Optional) copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 177 This example shows how to set the MST interface port priority for MSTI 3 on Ethernet port 3/1 to 64: switch# config t switch(config)# interface ethernet 3/1 switch(config-if)# spanning-tree mst 3 port-priority 64 switch(config-if)# exit switch(config)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 178: Configuring The Mst Port Cost
• For instance-id, you can specify a single instance, a range of instances separated by a hyphen, or a series of instances separated by a comma. The range is from 1 to 4094. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 179: Configuring The Mst Hello Time
Before You Begin Ensure that you are in the correct VDC (or enter the switchto vdc command). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 180: Configuring The Mst Forwarding-Delay Time
1 switch(config)# exit switch# Configuring the MST Forwarding-Delay Time You can set the forward delay timer for all MST instances on the device with one command. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 181 This example shows how to configure the forward-delay time of the device to 10 seconds: switch# config t switch(config)# spanning-time mst forward-time 10 switch(config)# exit switch# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 182: Configuring The Mst Maximum-Aging Time
Displays the MST configuration. Example: switch# show spanning-tree mst Step 5 copy running-config startup-config (Optional) Copies the running configuration to the startup configuration. Example: switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 183: Configuring The Mst Maximum-Hop Count
1 to 255, and the default value Example: is 20 hops. switch(config)# spanning-tree mst max-hops 40 Step 3 Exits MST configuration submode. exit Example: switch(config-mst)# exit switch# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 184: Configuring An Interface To Proactively Send Prestandard Mstp Messages-Cli Version
By default, interfaces on a device running MST send prestandard, rather than standard, MSTP messages after they receive a prestandard MSTP message from another interface. In Cisco NX-OS Release 4.0(2) and later releases, you can configure the interface to proactively send prestandard MSTP messages. That is, the specified interface would not have to wait to receive a prestandard MSTP message;...
Page 185: Specifying The Link Type For Mst-Cli Version
If you set the link to shared, STP falls back to 802.1D. Before You Begin Ensure that you are in the correct VDC (or enter the switchto vdc command). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 186 Displays the STP configuration. Example: switch# show spanning-tree Step 6 copy running-config startup-config (Optional) Copies the running configuration to the startup configuration. Example: switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 187: Reinitializing The Protocol For Mst
To display MST configuration information, perform one of the following tasks: Command Purpose show running-config spanning-tree [all] Displays STP information. show spanning-tree mst configuration Displays MST information. show spanning-tree mst [detail] Displays information about MST instances. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 188: Displaying And Clearing Mst Statistics-Cli Version
[detail] show spanning-tree vlan vlan-id bridge Displays information on the STP bridge. For information on the output of these commands, see the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Command Reference. Displaying and Clearing MST Statistics—CLI Version To display MST configuration information, perform one of the following tasks:...
Page 189 63 vlan 1303-1323 switch(config-mst)# instance 64 vlan 1324-1344 switch(config-mst)# exit switch(config)# interface ethernet 3/1 switch(config-if)# switchport switch(config-if)# no shutdown switch(config-if)# spanning-tree port type edge switch(congig-if)# exit Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 190: Additional References For Mst-Cli Version
Cisco Nexus 7000 Series NX-OS Release Notes Standards Standards Title IEEE 802.1Q-2006 (formerly known as IEEE 802.1s), — IEEE 802.1D-2004 (formerly known as IEEE 802.1w), IEEE 802.1D, IEEE 802.1t Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 191: Feature History For Configuring Mst--Cli Version
This table includes only the updates for those releases that have resulted in additions or changes to the feature. Table 16: Feature History for Configuring MSTs Feature Name Releases Feature Information No change. 4.2(1) No change. 4.1(2) Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 192 Configuring MST Using Cisco NX-OS Feature History for Configuring MST--CLI Version Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 193: Chapter 9 Configuring Stp Extensions Using Cisco Nx-Os
C H A P T E R Configuring STP Extensions Using Cisco NX-OS This chapter describes how to configure Spanning Tree Protocol (STP) extensions on Cisco NX-OS devices. This chapter includes the following sections: • Finding Feature Information, page 177 •...
Page 194: Stp Port Types
Note Bridge Assurance is supported only by Rapid PVST+ and MST. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 195 Figure 17: Network with Normal STP Topology This figure demonstrates a potential network problem when the device fails and you are not running Bridge Assurance. Figure 18: Network Problem without Running Bridge Assurance Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 196: Bpdu Guard
When you configure BPDU Guard globally, it is effective only on operational spanning tree edge ports. In a valid configuration, Layer 2 LAN edge interfaces do not receive BPDUs. A BPDU that is received by an edge Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 197: Bpdu Filtering
BPDUs are dropped if they are not in the allowed VLAN list and BPDU Guard is enabled on the port. In Cisco NX-OS Release 6.2(10) and later releases, the port will be error disabled when a BPDU is received on any VLAN and BPDU Guard is enabled on the port.
Page 198: Loop Guard
When you enable Root Guard on a port, Root Guard does not allow that port to become a root port. If a received BPDU triggers an STP convergence that makes that designated port become a root port, that port is Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 199: Applying Stp Extension Features
MST interoperates with Rapid PVST+ with no need for user configuration. The PVST simulation feature enables this interoperability. Note PVST simulation is enabled by default when you enable MST. By default, all interfaces on the device interoperate between MST and Rapid PVST+. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 200: High Availability For Stp
The software supports high availability for STP. However, the statistics and timers are not restored when STP restarts. The timers start again and the statistics begin from 0. See the Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide for complete information Note on high-availability features.
Page 201: Prerequisites For Stp Extensions
• If you configure the spanning-tree forward-delay time to below the default value, it can impact the system's ability to successfully perform a switchover supervisor at scale. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 202: Default Settings For Stp Extensions
These ports can be connected to any device. You can configure the port type either globally or per interface. By default, the spanning tree port type is normal. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 203 Step 3 switch(config)# exit Exits global configuration mode. Step 4 switch# show spanning-tree summary (Optional) Displays the STP configuration including STP port types if configured. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 204: Configuring Spanning Tree Edge Ports On Specified Interfaces
Before You Begin • Ensure that you are in the correct VDC (or enter theswitchto vdc command). • Ensure that STP is configured. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 205: Configuring Spanning Tree Network Ports On Specified Interfaces
Configuring Spanning Tree Network Ports on Specified Interfaces You can configure spanning tree network ports on specified interfaces. Bridge Assurance runs only on spanning tree network ports. This command has three states: Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 206 Step 4 switch(config-if)# exit Exits interface configuration mode. Step 5 switch# show spanning-tree interface type (Optional) slot/port Displays the STP configuration including the STP port type if configured. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 207: Enabling Bpdu Guard Globally
Enters global configuration mode. Step 2 switch(config)# spanning-tree port type edge Enables BPDU Guard by default on all spanning tree edge ports. By default, global BPDU Guard is disabled. bpduguard default Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 208: Enabling Bpdu Guard On Specified Interfaces
Note In Cisco NX-OS Release 6.2(10) and later releases, the port will be error disabled when a BPDU is received on any VLAN and BPDU Guard is enabled on the port.
Page 209 This example shows how to explicitly enable BPDU Guard on the Ethernet edge port 1/4: switch# config t switch(config)# interface ethernet 1/4 switch(config-if)# spanning-tree bpduguard enable switch(config-if)# exit switch(config)# Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 210: Enabling Bpdu Filtering Globally
Exits global configuration mode. Step 4 switch# show spanning-tree summary (Optional) Displays summary STP information. Step 5 switch# copy running-config startup-config (Optional) Copies the running configuration to the startup configuration. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 211: Enabling Bpdu Filtering On Specified Interfaces
2. switch(config)# interface type slot/port 3. Enter one of the following commands: 4. switch(config-if)# exit 5. (Optional) switch# show spanning-tree summary interface type slot/port detail 6. (Optional) switch(config)# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 212: Enabling Loop Guard Globally
Entering the Loop Guard command for the specified interface overrides the global Loop Guard command. Note Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 213: Enabling Loop Guard Or Root Guard On Specified Interfaces
You can run Loop Guard on spanning tree normal or network ports. You can run Root Guard on all Note spanning tree ports: normal, edge, or network. You can enable either Loop Guard or Root Guard on specified interfaces. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 214 This example shows Loop Guard is enabled on the specified interface. Step 4 switch(config-if)# exit Exits interface configuration mode. Step 5 switch(config)# interface type slot/port Specifies the interface to configure and enters interface configuration mode. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 215: Configuring Pvst Simulation Globally-Cli Version
SUMMARY STEPS 1. switch# config t 2. switch(config)# no spanning-tree mst simulate pvst global 3. switch(config)# exit 4. (Optional) switch# show spanning-tree summary 5. (Optional) switch# copy running-config startup-config Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 216: Configuring Pvst Simulation Per Port
You can block this automatic feature either globally or per port. Before You Begin Ensure that you are in the correct VDC (or enter the switchto vdc command). Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 217 Step 5 switch# show spanning-tree interface type slot/port detail (Optional) Displays detailed STP information. Step 6 switch(config)# copy running-config startup-config (Optional) Copies the running configuration to the startup configuration. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 218: Verifying The Stp Extension Configuration
{ethernet slot/port | port-channel channel-number} and instance. [detail] For information on the output of these commands, see the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Command Reference. Configuration Examples for STP Extension The following example shows how to configure the STP extensions:...
Page 219: Feature History For Configuring Stp Extensions-Cli Version
• BRIDGE-MIB Feature History for Configuring STP Extensions—CLI version This table includes only the updates for those releases that have resulted in additions or changes to the feature. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 220 Table 19: Feature History for Configuring STP Extensions Feature Name Releases Feature Information BPDU Guard 6.2(10) Added support for BPDU Guard error disable. No change. 4.2(1) — No change. 4.1(2) — Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 221: Appendix A Configuration Limits For Layer 2 Switching
Configuration Limits for Layer 2 Switching, page 205 Configuration Limits for Layer 2 Switching The configuration limits are documented in the Cisco Nexus 7000 Series NX-OS Verified Scalability Guide. Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 222 Configuration Limits for Layer 2 Switching Configuration Limits for Layer 2 Switching Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x...
Page 223 13, 27, 64, 90, 108, 142, 186 Rapid PVST+ 93, 96 Layer 2 switching superior TC While timer private VLANs version 96, 135, 139 Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x IN-1...
Page 224 VLANs secondary private VLANs ISSU switching forward delay time 98, 122 132, 133, 134 configuring per VLAN for Rapid PVST+ BPDUs description description forwarding port state description Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x IN-2...
Page 225 10, 14, 15, 19, 20 clearing name dynamically building path-cost method forwarding consistency port cost match on modules port priority static addresses pre-provisioning 10, 14, 15 verifying prestandard MSTP messages Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x IN-3...
Page 226 105, 118, 160 isolated VLANs 54, 56, 65 configuring for Rapid PVST+ licenses limitations Rapid PVST+ mapping 59, 85 port roles MST mapping ports 55, 63 community Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x IN-4...
Page 227 56, 58, 67 guidelines community interactions with other features isolated interoperation with IEEE 802.1D mapping to VLAN interfaces 90, 95, 105 interoperation with IEEE 802.1Q private VLANs 90, 105 Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x IN-5...
Page 228 6, 26, 59, 90, 106, 139, 184 description private VLANs STP topology 90, 106, 139 troubleshooting STP extensions SVIs VDCs VLAN interfaces VLANs switch priority VLAN 3, 34 configuring Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x IN-6...
Page 229 10, 132 VLAN states and STP configuring MAC addresses VLAN statistics 24, 44, 46, 47 clearing guidelines displaying mode VLAN traffic transparent mode and routing distribution Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x IN-7...
Page 230 Index Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.x IN-8...

Cisco Nexus 7000 Series Configuration Manual

Preface

Audience

CHAPTER 1 New and Changed Information

CHAPTER 2 Overview

CHAPTER 3 Configuring Layer 2 Switching

CHAPTER 4 Configuring Vlans

CHAPTER 5 Configuring VTP

CHAPTER 6 Configuring Private Vlans Using NX-OS

CHAPTER 7 Configuring Rapid PVST+ Using Cisco NX-OS

CHAPTER 8 Configuring MST Using Cisco NX-OS

Chapter 9 Configuring STP Extensions Using Cisco NX-OS

Appendix A Configuration Limits for Layer 2 Switching

Quick Links

Related Manuals for Cisco Nexus 7000 Series

Summary of Contents for Cisco Nexus 7000 Series