Cisco Nexus 5000 Series NX-OS Interfaces Configuration Guide,
Release 5.2(1)N1(1)
First Published: July 02, 2012
Last Modified: July 02, 2012
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Text Part Number: 78-26881-OL
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C O N T E N T S
P r e f a c e
Preface ix
Audience ix
Document Conventions ix
Documentation Feedback x
C H A P T E R 1
C H A P T E R 2
Obtaining Documentation and Submitting a Service Request xi
New and Changed Information for this Release 1
New and Changed Information for this Release 1 |
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Configuring Layer 2 Interfaces 3 |
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Information About Ethernet Interfaces |
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About the Interface Command 3 |
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Information About Unified Ports 4 |
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Guidelines and Limitations for Unified Ports |
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About the Unidirectional Link Detection Parameter |
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Default UDLD Configuration |
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UDLD Aggressive and Nonaggressive Modes |
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Interface Speed 6 |
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About the Cisco Discovery Protocol |
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Default CDP Configuration |
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About the Error-Disabled State |
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About Port Profiles 8 |
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Guidelines and Limitations for Port Profiles |
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About the Debounce Timer Parameters 9 |
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About MTU Configuration 9
Configuring Ethernet Interfaces 10
Configuring a Layer 3 Interface on a Cisco Nexus 5500 Platform Switch 10
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C H A P T E R 3
Configuring Unified Ports 10 |
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Configuring the UDLD Mode 12 |
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Configuring Interface Speed |
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Disabling Link Negotiation |
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Configuring the CDP Characteristics 14 |
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Enabling or Disabling CDP |
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Enabling the Error-Disabled Detection |
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Enabling the Error-Disabled Recovery |
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Configuring the Error-Disabled Recovery Interval 18 |
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Port Profiles 19 |
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Creating a Port Profile |
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Modifying a Port Profile 20 |
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Enabling a Specific Port Profile 21 |
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Inheriting a Port Profile |
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Removing an Inherited Port Profile |
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Assigning a Port Profile to a Range of Interfaces 24 |
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Removing a Port Profile from a Range of Interfaces 25 |
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Configuration Examples for Port Profiles 26 |
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Configuring the Debounce Timer |
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Configuring the Description Parameter |
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Disabling and Restarting Ethernet Interfaces |
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Displaying Interface Information 29 |
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Default Physical Ethernet Settings |
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Configuring Layer 3 Interfaces 33 |
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Information About Layer 3 Interfaces 33 |
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Routed Interfaces |
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Subinterfaces 34 |
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VLAN Interfaces |
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Loopback Interfaces 35 |
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Tunnel Interfaces |
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Licensing Requirements for Layer 3 Interfaces |
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Guidelines and Limitations for Layer 3 Interfaces 36 |
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Default Settings for Layer 3 Interfaces 36 |
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Configuring Layer 3 Interfaces |
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Contents
Configuring a Routed Interface 36 |
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Configuring a Subinterface 37 |
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Configuring the Bandwidth on an Interface |
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Configuring a VLAN Interface 39 |
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Configuring a Loopback Interface 40 |
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Assigning an Interface to a VRF 40 |
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Verifying the Layer 3 Interfaces Configuration |
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Monitoring Layer 3 Interfaces 42 |
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Configuration Examples for Layer 3 Interfaces |
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Related Documents for Layer 3 Interfaces 44 |
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MIBs for Layer 3 Interfaces 44
Standards for Layer 3 Interfaces 44
C H A P T E R 4
Configuring Port Channels 45
Information About Port Channels 45
Understanding Port Channels 45
Guidelines and Limitations for Port Channel Configuration 46
Compatibility Requirements 47
Load Balancing Using Port Channels 48
Understanding LACP 51
LACP Overview 51
LACP ID Parameters 52
Channel Modes 52
LACP Marker Responders 53
LACP-Enabled and Static Port Channel Differences 54
Configuring Port Channels 54
Creating a Port Channel 54
Adding a Port to a Port Channel 55
Configuring Load Balancing Using Port Channels 55
Configuring Hardware Hashing for Multicast Traffic 57
Enabling LACP 57
Configuring the Channel Mode for a Port 58
Configuring the LACP Fast Timer Rate 59
Configuring the LACP System Priority and System ID 60
Configuring the LACP Port Priority 60
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Disabling LACP Graceful Convergence 61
Reenabling LACP Graceful Convergence 62
Verifying Port Channel Configuration 63
Verifying the Load-Balancing Outgoing Port ID 64
C H A P T E R 5
Configuring Virtual Port Channels 65
Information About vPCs 65
vPC Overview 65
Terminology 67
vPC Terminology 67
Fabric Extender Terminology 67
Supported vPC Topologies 68
Cisco Nexus 5000 Series Switch vPC Topology 68
Single Homed Fabric Extender vPC Topology 69
Dual Homed Fabric Extender vPC Topology 70
vPC Domain 70
Peer-Keepalive Link and Messages 71
Compatibility Parameters for vPC Peer Links 71
Configuration Parameters That Must Be Identical 71
Configuration Parameters That Should Be Identical 73
Graceful Type-1 Check 73
Per-VLAN Consistency Check 74
vPC Auto-Recovery 74
vPC Peer Links 74
vPC Peer Link Overview 74
vPC Number 75
vPC Interactions with Other Features 76
Configuring vPC Peer Links and Links to the Core 76 vPC and LACP 77
vPC Peer Links and STP 77
vPC and ARP 78
CFSoE 78
vPC Peer Switch 79
Guidelines and Limitations for vPCs 79
Configuring vPCs 80
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Enabling vPCs 80
Disabling vPCs 80
Creating a vPC Domain 81
Configuring a vPC Keepalive Link and Messages 82
Creating a vPC Peer Link 84
Checking the Configuration Compatibility 85
Enabling vPC Auto-Recovery 86
Suspending Orphan Ports on a Secondary Switch in a vPC Topology 87
Creating an EtherChannel Host Interface 88
Moving Other Port Channels into a vPC 89
Manually Configuring a vPC Domain MAC Address 90
Manually Configuring the System Priority 91
Manually Configuring a vPC Peer Switch Role 92
Configuring the vPC Peer Switch 93
Configuring a Pure vPC Peer Switch Topology 93
Configuring a Hybrid vPC Peer Switch Topology 94
Verifying the vPC Configuration 95
Viewing The Graceful Type-1 Check Status 96
Viewing A Global Type-1 Inconsistency 97
Viewing An Interface-Specific Type-1 Inconsistency 98
Viewing a Per-VLAN Consistency Status 99
vPC Example Configurations 101
Dual Homed Fabric Extender vPC Configuration Example 101
Single Homed Fabric Extender vPC Configuration Example 103
vPC Default Settings 105
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Contents
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This preface contains the following sections:
• Audience, page ix
• Document Conventions, page ix
• Documentation Feedback , page x
• Obtaining Documentation and Submitting a Service Request, page xi
This publication is for experienced network administrators who configure and maintain Cisco Nexus devices and Cisco Nexus 2000 Series Fabric Extenders.
Command descriptions use the following conventions:
Convention |
Description |
bold |
Bold text indicates the commands and keywords that you enter literally |
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as shown. |
Italic |
Italic text indicates arguments for which the user supplies the values. |
[x] |
Square brackets enclose an optional element(keyword or argument). |
[x | y] |
Squarebracketsenclosingkeywordsorargumentsseparatedbyavertical |
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bar indicate an optional choice. |
{x | y} |
Braces enclosing keywords or arguments separated by a vertical bar |
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indicate a required choice. |
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Preface
Convention |
Description |
[x {y | z}] |
Nested set of square brackets or braces indicate optional or required |
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choices within optional or required elements. Braces and a vertical bar |
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within square brackets indicate a required choice within an optional |
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element. |
variable |
Indicatesavariableforwhichyousupplyvalues,incontextwhereitalics |
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cannot be used. |
string |
A nonquoted set of characters. Do not use quotation marks around the |
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string or the string will include the quotation marks. |
Examples use the following conventions: |
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Convention |
Description |
screen font |
Terminalsessionsandinformationtheswitchdisplaysareinscreenfont. |
boldface screen font |
Information you must enter is in boldface screen font. |
italic screen font |
Arguments for which you supply values are in italic screen font. |
< > |
Nonprinting characters, such as passwords, are in angle brackets. |
[ ] |
Default responses to system prompts are in square brackets. |
!, # |
An exclamation point (!) or a pound sign (#) at the beginning of a line |
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of code indicates a comment line. |
This document uses the following conventions:
Note Means reader take note. Notes contain helpful suggestions or references to material not covered in the manual.
Caution Means reader be careful. Inthissituation,youmightdosomethingthatcouldresultinequipmentdamage or loss of data.
Documentation Feedback
Toprovidetechnicalfeedbackonthisdocument,ortoreportanerrororomission,pleasesendyourcomments to nexus5k-docfeedback@cisco.com . We appreciate your feedback.
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Preface
Obtaining Documentation and Submitting a Service Request
Forinformationonobtainingdocumentation,submittingaservicerequest,andgatheringadditionalinformation, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at:
http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html
Subscribe to the What's New in Cisco Product Documentation as a Really Simple Syndication (RSS) feed and set content to be delivered directly to your desktop using a reader application. The RSS feeds are a free service and Cisco currently supports RSS version 2.0.
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C H A P T E R 1
The following table provides an overview of the significant changes to this guide for this current release. The table does not provide an exhaustive list of all changes made to the configuration guides or of the new features in this release.
• New and Changed Information for this Release, page 1
Thefollowingtableprovidesanoverviewofthesignificantchangestothisguideforthiscurrentrelease. The tabledoesnotprovideanexhaustivelistofallchangesmadetotheconfigurationguidesorofthenewfeatures in this release.
Table 1: New Features |
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Description |
Where Documented |
IPv6 |
AddedsupportforIPv6addressing. |
• Routed Interfaces, on page |
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• Configuring a Subinterface, |
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on page 37 |
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• Configuring the Bandwidth |
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on an Interface, on page 38 |
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• Configuring a VLAN |
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Interface, on page 39 |
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• Configuring a Loopback |
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Interface, on page 40 |
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• Assigning an Interface to a |
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VRF, on page 40 |
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New and Changed Information for this Release
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C H A P T E R 2
This chapter contains the following sections:
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Information About Ethernet Interfaces, |
page 3 |
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Configuring Ethernet Interfaces, |
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10 |
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Displaying Interface Information, |
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29 |
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Default Physical Ethernet Settings , page 31 |
The Ethernet ports can operate as standard Ethernet interfaces connected to servers or to a LAN.
TheEthernetinterfacesalsosupportFibreChanneloverEthernet(FCoE). FCoEallowsthephysicalEthernet link to carry both Ethernet and Fibre Channel traffic.
The Ethernet interfaces are enabled by default.
You can enable the various capabilities of the Ethernet interfaces on a per-interface basis using the interface command. When you enter the interface command, you specify the following information:
• Interface type—All physical Ethernet interfaces use the ethernet keyword.
•Slot number
◦Slot 1 includes all the fixed ports.
◦Slot 2 includes the ports on the upper expansion module (if populated).
◦Slot 3 includes the ports on the lower expansion module (if populated).
◦Slot 4 includes the ports on the lower expansion module (if populated).
•Port number— Port number within the group.
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TheinterfacenumberingconventionisextendedtosupportusewithaCiscoNexus2000SeriesFabricExtender as follows:
switch(config)# interface ethernet [chassis/]slot/port
•Chassis ID is an optional entry to address the ports of a connected Fabric Extender. The chassis ID is configuredonaphysicalEthernetorEtherChannelinterfaceontheswitchtoidentifytheFabricExtender discovered via the interface. The chassis ID ranges from 100 to 199.
Information About Unified Ports
Cisco Nexus unified ports allow you to configure a physical port on a Cisco Nexus 5500 Platform switch as a 1/10-Gigabit Ethernet, Fibre Channel over Ethernet (FCoE), or 1-, 2-, 4-, 8-Gigabit native Fibre Channel port.
Currently, most networks have two types of switches for different types of networks. For example, LAN switches carry Ethernet traffic up to Catalyst switches and SAN switches carry FC traffic from servers to MDS switches. With unified port technology, you can deploy a unified platform, unified device, and unified wire approach. Unified ports allow you to move from an existing segregated platform approach where you choose LAN and SAN port options to transition to a single, unified fabric that is transparent and consistent with existing practices and management software. A unified fabric includes the following:
•Unified platform—Uses the same hardware platform and the same software code level and certifies it once for your LAN and SAN environments.
•Unified device—Runs LAN and SAN services on the same platform switch. The unified device allows you to connect your Ethernet and Fibre Channel cables to the same device.
•Unified wire—Converges LAN and SAN networks on a single converged network adapter (CNA) and connects them to your server.
A unified fabric allows you to manage Ethernet and FCoE features independently with existing Cisco tools.
•Ethernet ports and Fibre Channel ports must be configured in the following order:
•Fibre Channel ports must be configured from the last port of the module.
•Ethernet ports must be configured from the first port of the module.
If the order is not followed, the following errors are displayed:
ERROR: Ethernet range starts from first port of the module
ERROR: FC range should end on last port of the module
•On the Cisco Nexus 5548UP switch, the 32 ports of the main slot (slot1) are unified ports. The Ethernet ports start from port 1/1 to port 1/32. The Fibre Channel ports start from port 1/32 backwards to port 1/1.
•FortheCiscoNexus5596Tswitch,thelast16ports(ports33-48)areFiberChannelandareconfigurable as unified ports. The first 32 ports (1-32) are 10GBase-T Ethernet ports only and cannot be configured as unified ports.
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About the Unidirectional Link Detection Parameter
TheCisco-proprietaryUnidirectionalLinkDetection(UDLD)protocolallowsportsthatareconnectedthrough fiberopticsorcopper(forexample,Category5cabling)Ethernetcablestomonitorthephysicalconfiguration ofthecablesanddetectwhenaunidirectionallinkexists.Whentheswitchdetectsaunidirectionallink,UDLD shuts down the affected LAN port and alerts the user. Unidirectional links can cause a variety of problems, including spanning tree topology loops.
UDLD is a Layer 2 protocol that works with the Layer 1 protocols to determine the physical status of a link. At Layer 1, autonegotiation takes care of physical signaling and fault detection. UDLD performs tasks that autonegotiationcannotperform,suchasdetectingtheidentitiesofneighborsandshuttingdownmisconnected LANports. WhenyouenablebothautonegotiationandUDLD,Layer1andLayer2detectionsworktogether to prevent physical and logical unidirectional connections and the malfunctioning of other protocols.
A unidirectional link occurs whenever traffic transmitted by the local device over a link is received by the neighborbuttraffictransmittedfromtheneighborisnotreceivedbythelocaldevice.Ifoneofthefiberstrands inapairisdisconnected,aslongasautonegotiationisactive,thelinkdoesnotstayup. Inthiscase,thelogical link is undetermined, and UDLD does not take any action. If both fibers are working normally at Layer 1, thenUDLDatLayer2determineswhetherthosefibersareconnectedcorrectlyandwhethertrafficisflowing bidirectionally between the correct neighbors. This check cannot be performed by autonegotiation, because autonegotiation operates at Layer 1.
A Cisco Nexus device periodically transmits UDLD frames to neighbor devices on LAN ports with UDLD enabled. If the frames are echoed back within a specific time frame and they lack a specific acknowledgment (echo), the link is flagged as unidirectional and the LAN port is shut down. Devices on both ends of the link must support UDLD in order for the protocol to successfully identify and disable unidirectional links.
Note By default, UDLD is locally disabled on copper LAN ports to avoid sending unnecessary control traffic on this type of media.
The following figure shows an example of a unidirectional link condition. Device B successfully receives traffic from Device A on the port. However, Device A does not receive traffic from Device B on the same port. UDLD detects the problem and disables the port.
Figure 1: Unidirectional Link
The following table shows the default UDLD configuration.
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Table 2: UDLD Default Configuration |
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Feature |
Default Value |
UDLD global enable state |
Globally disabled |
UDLD aggressive mode |
Disabled |
UDLD per-port enable state for fiber-optic media |
Enabled on all Ethernet fiber-optic LAN ports |
UDLDper-portenablestatefortwisted-pair(copper) |
Disabled on all Ethernet 10/100 and 1000BASE-TX |
media |
LAN ports |
UDLD aggressive mode is disabled by default. You can configure UDLD aggressive mode only on point-to-pointlinksbetweennetworkdevicesthatsupportUDLDaggressivemode.IfUDLDaggressivemode is enabled, when a port on a bidirectional link that has a UDLD neighbor relationship established stops receivingUDLDframes,UDLDtriestoreestablishtheconnectionwiththeneighbor.Aftereightfailedretries, the port is disabled.
To prevent spanning tree loops, nonaggressive UDLD with the default interval of 15 seconds is fast enough to shut down a unidirectional link before a blocking port transitions to the forwarding state (with default spanning tree parameters).
When you enable the UDLD aggressive mode, the following occurs:
•One side of a link has a port stuck (both transmission and receive)
•One side of a link remains up while the other side of the link is down
In these cases, the UDLD aggressive mode disables one of the ports on the link, which prevents traffic from being discarded.
Interface Speed
The 5596T switch has 48 base board ports and 3 GEM slots. The first 32 ports are 10GBase-T ports the last 16 ports are SFP+ ports. The 10GBase-T ports support a speed of 1-Gigabit, 10-Gigabit, or Auto. The Auto setting automatically negotiates with the link parser to select either 1-Gigabit or 10-Gigabit speed.
TheCiscoDiscoveryProtocol(CDP)isadevicediscoveryprotocolthatrunsoverLayer2(thedatalinklayer) on all Cisco-manufactured devices (routers, bridges, access servers, and switches) and allows network management applications to discover Cisco devices that are neighbors of already known devices. With CDP, network management applications can learn the device type and the Simple Network Management Protocol (SNMP)agentaddressofneighboringdevicesrunninglower-layer,transparentprotocols.Thisfeatureenables applications to send SNMP queries to neighboring devices.
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CDPrunsonallmediathatsupportSubnetworkAccessProtocol(SNAP).BecauseCDPrunsoverthedata-link layer only, two systems that support different network-layer protocols can learn about each other.
Each CDP-configured device sends periodic messages to a multicast address, advertising at least one address atwhichitcanreceiveSNMPmessages.Theadvertisementsalsocontaintime-to-live,orholdtimeinformation, which is the length of time a receiving device holds CDP information before discarding it. Each device also listens to the messages sent by other devices to learn about neighboring devices.
The switch supports both CDP Version 1 and Version 2.
The following table shows the default CDP configuration.
Table 3: Default CDP Configuration |
|
Feature |
Default Setting |
CDP interface state |
Enabled |
CDP timer (packet update frequency) |
60 seconds |
CDP holdtime (before discarding) |
180 seconds |
CDP Version-2 advertisements |
Enabled |
About the Error-Disabled State
An interface is in the error-disabled (err-disabled) state when the inteface is enabled administratively (using the no shutdown command) but disabled at runtime by any process. For example, if UDLD detects a unidirectional link, the interface is shut down at runtime. However, because the interface is administratively enabled, the interface status displays as err-disabled. Once an interface goes into the err-disabled state, you mustmanuallyreenableitoryoucanconfigureanautomatictimeoutrecoveryvalue.Theerr-disableddetection is enabled by default for all causes. The automatic recovery is not configured by default.
When an interface is in the err-disabled state, use the errdisable detect cause command to find information about the error.
Youcanconfiguretheautomaticerr-disabledrecoverytimeoutforaparticularerr-disabledcausebychanging the time variable.
The errdisable recovery cause command provides automatic recovery after 300 seconds. To change the recoveryperiod,usetheerrdisablerecoveryinterval commandtospecifythetimeoutperiod.Youcanspecify 30 to 65535 seconds.
If you do not enable the err-disabled recovery for the cause, the interface stays in the err-disabled state until you enter the shutdown and no shutdown commands. If the recovery is enabled for a cause, the interface is brought out of the err-disabled state and allowed to retry operation once all the causes have timed out. Use the show interface status err-disabled command to display the reason behind the error.
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About Port Profiles
You can create a port profile that contains many interface commands and apply that port profile to a range of interfaces on the Cisco Nexus device. Port profiles can be applied to the following interface types:
•Ethernet
•VLAN network interface
•Port channel
A command that is included in a port profile can be configured outside of the port profile. If the new configuration in the port profile conflicts with the configurations that exist outside the port profile, the commandsconfiguredforaninterfaceinconfigurationterminalmodehavehigherprioritythanthecommands in the port profile. If changes are made to the interface configuration after a port profile is attached to it, and theconfigurationconflictswiththatintheportprofile,theconfigurationsintheinterfacewillbegivenpriority.
You inherit the port profile when you attach the port profile to an interface or range of interfaces, When you attach, or inherit, a port profile to an interface or range of interfaces, the switch applies all the commands in that port profile to the interfaces.
You can have one port profile inherit the settings from another port profile. Inheriting another port profile allows the initial port profile to assume all of the commands of the second, inherited, port profile that do not conflict with the initial port profile. Four levels of inheritance are supported. The same port profile can be inherited by any number of port profiles.
To apply the port profile configurations to the interfaces, you must enable the specific port profile. You can configureandinheritaportprofileontoarangeofinterfacespriortoenablingtheportprofile;youthenenable that port profile for the configurations to take effect on the specified interfaces.
When you remove a port profile from a range of interfaces, the switch undoes the configuration from the interfacesfirstandthenremovestheportprofilelinkitself.Whenyouremoveaportprofile,theswitchchecks the interface configuration and either skips the port profile commands that have been overridden by directly entered interface commands or returns the command to the default value.
Ifyouwanttodeleteaportprofilethathasbeeninheritedbyotherportprofiles,youmustremovetheinheritance before you can delete the port profile.
Youcanchooseasubsetofinterfacesfromwhichtoremoveaportprofilefromamongthatgroupofinterfaces that you originally applied the profile. For example, if you configured a port profile and configured ten interfaces to inherit that port profile, you can remove the port profile from just some of the specified ten interfaces. The port profile continues to operate on the remaining interfaces to which it is applied.
Ifyoudeleteaspecificconfigurationforaspecifiedrangeofinterfacesusingtheinterfaceconfigurationmode, that configuration is also deleted from the port profile for that range of interfaces only. For example, if you have a channel group inside a port profile and you are in the interface configuration mode and you delete that port channel, the specified port channel is also deleted from the port profile as well.
After you inherit a port profile on an interface or range of interfaces and you delete a specific configuration value, that port profile configuration will not operate on the specified interfaces.
If you attempt to apply a port profile to the wrong type of interface, the switch returns an error.
When you attempt to enable, inherit, or modify a port profile, the switch creates a checkpoint. If the port profile configuration fails, the switch rolls back to the prior configuration and returns an error. A port profile is never only partially applied.
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Port profiles have the following configuration guidelines and limitations:
•Each port profile must have a unique name across interface types and the network.
•Commands that you enter under the interface mode take precedence over the port profile’s commands if there is a conflict. However, the port profile retains that command in the port profile.
•The port profile’s commands take precedence over the default commands on the interface, unless the default command explicitly overrides the port profile command.
•After you inherit a port profile onto an interface or range of interfaces, you can override individual configuration values by entering the new value at the interface configuration level. If you remove the individual configuration values at the interface configuration level, the interface uses the values in the port profile again.
•There are no default configurations associated with a port profile.
•A subset of commands are available under the port profile configuration mode, depending on which interface type that you specify.
•You cannot use port profiles with Session Manager.
About the Debounce Timer Parameters
The port debounce time is the amount of time that an interface waits to notify the supervisor of a link going down. During this time, the interface waits to see if the link comes back up. The wait period is a time when traffic is stopped.
You can enable the debounce timer for each interface and specify the delay time in milliseconds.
Caution When you enable the port debounce timer the link up and link down detections are delayed, resulting in alossoftrafficduringthedebounceperiod.Thissituationmightaffecttheconvergenceandreconvergence of some protocols.
The Cisco Nexus device switch does not fragment frames. As a result, the switch cannot have two ports in thesameLayer2domainwithdifferentmaximumtransmissionunits(MTUs).Aper-physicalEthernetinterface MTUisnotsupported. Instead,theMTUissetaccordingtotheQoSclasses. YoumodifytheMTUbysetting class and policy maps.
Note Whenyoushowtheinterfacesettings,adefaultMTUof1500isdisplayedforphysicalEthernetinterfaces and a receive data field size of 2112 is displayed for Fibre Channel interfaces.
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Configuring Layer 2 Interfaces
Configuring Ethernet Interfaces
The section includes the following topics:
On Cisco Nexus devices, you can configure a Layer 3 interface.
You can change a Layer 3 interface into a Layer 2 interface by using the switchport command. You can change a Layer 2 interface into a Layer 3 interface by using the no switchport command.
Note
Procedure
|
Command or Action |
Purpose |
Step 1 |
switch# configure terminal |
Enters configuration mode. |
Step 2 |
switch(config)# interface ethernet slot/port |
Entersconfigurationmodeforthespecified |
|
|
interface. |
Step 3 |
switch(config-if)# no switchport |
Selects the Layer 3 interface. |
Step 4 |
switch(config-if)# no shutdown |
Restarts the interface. |
This example shows how to configure a Layer 3 interface:
switch# configure terminal switch(config)# interface ethernet 1/2 switch(config-if)# no switchport switch(config-if)# no shutdown
Before You Begin
Confirm that you have a supported Cisco Nexus switch. Unified Ports are available on the following Cisco Nexus switches:
•Cisco Nexus 5596T
•Cisco Nexus 5548UP
•Cisco Nexus 5596UP
•Cisco Nexus 5548P switch with an installed Cisco N55-M16UP expansion module
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Configuring Unified Ports
Ifyou'reconfiguringaunifiedportasFibreChannelorFCoE,confirmthatyouhaveenabledthe feature fcoe command.
Procedure
|
Command or Action |
Purpose |
|
Step 1 |
switch# configure terminal |
Enters global configuration mode. |
|
Step 2 |
switch(config) # slot slot number |
Identifies the slot on the switch. |
|
Step 3 |
switch(config-slot) # port port |
ConfiguresaunifiedportasanativeFibreChannelport |
|
|
number type {ethernet | fc} |
and an Ethernet port. |
|
|
|
• type—Specifies the type of port to configure on |
|
|
|
|
a slot in a chassis. |
|
|
• ethernet—Specifies an Ethernet port. |
|
|
|
• fc—Specifies a Fibre Channel (FC) port. |
|
|
|
Note |
Changingunifiedportsonanexpansionmodule |
|
|
|
(GEM)requiresthatyoupowercycletheGEM |
|
|
|
card. You do not have to reboot the entire |
|
|
|
switch for changes to take effect. |
Step 4 |
switch(config-slot) # copy |
Copies the running configuration to the startup |
|
|
running-config startup-config |
configuration. |
|
Step 5 |
switch(config-slot) # reload |
Reboots the switch. |
|
Step 6 |
switch(config)#noport portnumber |
Removes the unified port. |
|
|
type fc |
|
|
ThisexampleshowshowtoconfigureaunifiedportonaCiscoNexus5548UPswitchorCiscoNexus5596UP
switch:
switch# configure terminal switch(config)# slot 1 switch(config-slot)# port 32 type fc
switch(config-slot)# copy running-config startup-config switch(config-slot)# reload
This example shows how to configure 20 ports as Ethernet ports and 12 as FC ports:
switch# configure terminal switch(config)# slot 1 switch(config-slot)# port 21-32 type fc
switch(config-slot)# copy running-config startup-config switch(config-slot)# reload
This example shows how to configure a unified port on a Cisco N55-M16UP expansion module:
switch# configure terminal switch(config)# slot 2 switch(config-slot)# port 16 type fc
switch(config-slot)# copy running-config startup-config switch(config-slot)# poweroff module 2 switch(config-slot)# no poweroff module 2
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Configuring Layer 2 Interfaces
Configuring the UDLD Mode
You can configure normal or aggressive unidirectional link detection (UDLD) modes for Ethernet interfaces on devices configured to run UDLD. Before you can enable a UDLD mode for an interface, you must make sure that UDLD is already enabled on the device that includes the interface. UDLD must also be enabled on the other linked interface and its device.
TousethenormalUDLDmode,youmustconfigureoneoftheportsfornormalmodeandconfiguretheother port for the normal or aggressive mode. To use the aggressive UDLD mode, you must configure both ports for the aggressive mode.
Note Before you begin, UDLD must be enabled for the other linked port and its device.
Procedure
|
Command or Action |
Purpose |
Step 1 |
switch# configure terminal |
Enters configuration mode. |
Step 2 |
switch(config)# feature udld |
Enables UDLD for the device. |
Step 3 |
switch(config)# no feature udld |
Disables UDLD for the device. |
Step 4 |
switch(config)# show udld global |
Displays the UDLD status for the device. |
Step 5 |
switch(config)# interface type slot/port |
Specifies an interface to configure, and enters |
|
|
interface configuration mode. |
Step 6 |
switch(config-if)# udld {enable | disable |
Enables the normal UDLD mode, disables |
|
| aggressive} |
UDLD,orenablestheaggressiveUDLDmode. |
Step 7 |
switch(config-if)# show udld interface |
Displays the UDLD status for the interface. |
This example shows how to enable the UDLD for the switch:
switch# configure terminal switch(config)# feature udld
This example shows how to enable the normal UDLD mode for an Ethernet port:
switch# configure terminal switch(config)# interface ethernet 1/4 switch(config-if)# udld enable
This example shows how to enable the aggressive UDLD mode for an Ethernet port:
switch# configure terminal switch(config)# interface ethernet 1/4 switch(config-if)# udld aggressive
This example shows how to disable UDLD for an Ethernet port:
switch# configure terminal
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switch(config)# interface ethernet 1/4 switch(config-if)# udld disable
This example shows how to disable UDLD for the switch:
switch# configure terminal switch(config)# no feature udld
Configuring Interface Speed
The first 32 ports of a Cisco Nexus 5596T switch are switchable 1-Gigabit and 10-Gigabit ports. You can also configure them to auto-negotiate to either 1-Gigabit or 10-Gigabit. The last ports 33-48 are SFP+ ports and do not support auto negotiation.
Note Iftheinterfaceandtransceiverspeedismismatched,theSFPvalidationfailedmessageisdisplayedwhen you enter the show interface ethernet slot/port command. For example, if you insert a 1-Gigabit SFP transceiver into a port without configuring the speed 1000 command, you will get this error. By default, all ports are 10 Gigabits.
Procedure
|
Command or Action |
Purpose |
Step 1 |
switch# configure terminal |
Enters global configuration mode. |
Step 2 |
switch(config)# interface |
Enters interface configuration mode for the specified interface. |
|
type slot/port |
This interface must have a 1-Gigabit Ethernet SFP transceiver |
|
|
inserted into it. |
Step 3 switch(config-if)# speed speed
Sets the speed for a physical Ethernet interface.
For Cisco Nexus 5500 series switches, the speed argument can be set to one of the following:
•1000—1 Gbps
•10000—10Gbps
•auto
Note 100 Mbps is not a supported speed for the Cisco Nexus 5596 switch or CU-96 GEM card.
For the Cisco Nexus 5596T switch, the base board ports support 1 Gbps and 10 Gbps. On the 10GBase-T ports you can also choose auto.
The following example shows how to set the speed for a 1-Gigabit Ethernet port:
switch# configure terminal switch(config)# interface ethernet 1/4 switch(config-if)# speed 1000
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Configuring Layer 2 Interfaces
Disabling Link Negotiation
Youcandisablelinknegotiationusingthenonegotiateauto command.Bydefault,auto-negotiationisenabled on 1-Gigabit ports and disabled on 10-Gigabit ports.
This command is equivalent to the Cisco IOS speed non-negotiate command.
Note We do not recommend that you enable auto negotiation on 10-Gigabit ports. Enabling auto-negotiation on 10-Gigabit ports brings the link down. By default, link negotiation is disabled on 10-Gigabit ports.
Procedure
|
Command or Action |
Purpose |
|
Step 1 |
switch# configure terminal |
Enters configuration mode. |
|
Step 2 |
switch(config)# interface ethernet |
Selects the interface and enters interface mode. |
|
|
slot/port |
|
|
Step 3 |
switch(config-if)#nonegotiateauto |
Disables link negotiation on the selected Ethernet |
|
|
|
interface (1-Gigabit port). |
|
Step 4 |
switch(config-if)# negotiate auto |
(Optional) |
|
|
|
Enables link negotiation on the selected Ethernet |
|
|
|
interface. The default for 1-Gigabit ports is enabled. |
|
|
|
Note |
Thiscommandisnotapplicablefor10GBase-T |
|
|
|
ports.Itshouldnotbeusedon10GBase-Tports. |
This example shows how to disable auto negotiation on a specified Ethernet interface (1-Gigabit port): switch# configure terminal
switch(config)# interface ethernet 1/1 switch(config-if)# no negotiate auto switch(config-if)#
This example shows how to enable auto negotiation on a specified Ethernet interface (1-Gigabit port): switch# configure terminal
switch(config)# interface ethernet 1/5 switch(config-if)# negotiate auto switch(config-if)#
You can configure the frequency of Cisco Discovery Protocol (CDP) updates, the amount of time to hold the information before discarding it, and whether or not to send Version-2 advertisements.
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Procedure
|
Command or Action |
Purpose |
Step 1 |
switch# configure terminal |
Enters configuration mode. |
Step 2 |
switch(config)# [no] cdp |
(Optional) |
|
advertise {v1 | v2 } |
Configures the version to use to send CDP advertisements. |
|
|
Version-2 is the default state. |
|
|
Use the no form of the command to return to its default |
|
|
setting. |
Step 3 |
switch(config)# [no] cdp format |
(Optional) |
|
device-id {mac-address | |
Configures the format of the CDP device ID. The default is |
|
serial-number | system-name} |
the system name, which can be expressed as a fully qualified |
|
|
domain name. |
|
|
Use the no form of the command to return to its default |
|
|
setting. |
Step 4 |
switch(config)# [no] cdp |
(Optional) |
|
holdtime seconds |
Specifies the amount of time a receiving device should hold |
|
|
the information sent by your device before discarding it. The |
|
|
range is 10 to 255 seconds; the default is 180 seconds. |
|
|
Use the no form of the command to return to its default |
|
|
setting. |
Step 5 |
switch(config)# [no] cdp timer |
(Optional) |
|
seconds |
Sets the transmission frequency of CDP updates in seconds. |
|
|
The range is 5 to 254; the default is 60 seconds. |
|
|
Use the no form of the command to return to its default |
|
|
setting. |
This example shows how to configure CDP characteristics:
switch# configure terminal switch(config)# cdp timer 50 switch(config)# cdp holdtime 120 switch(config)# cdp advertise v2
Enabling or Disabling CDP
You can enable or disable CDP for Ethernet interfaces. This protocol works only when you have it enabled on both interfaces on the same link.
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Configuring Layer 2 Interfaces
Procedure
|
Command or Action |
Purpose |
Step 1 |
switch# configure terminal |
Enters configuration mode. |
Step 2 |
switch(config)#interface type slot/port |
Entersinterfaceconfigurationmodeforthespecified |
|
|
interface. |
Step 3 |
switch(config-if)# cdp enable |
Enables CDP for the interface. |
|
|
To work correctly, this parameter must be enabled |
|
|
for both interfaces on the same link. |
Step 4 |
switch(config-if)# no cdp enable |
Disables CDP for the interface. |
This example shows how to enable CDP for an Ethernet port:
switch# configure terminal switch(config)# interface ethernet 1/4 switch(config-if)# cdp enable
This command can only be applied to a physical Ethernet interface.
Enabling the Error-Disabled Detection
You can enable error-disable (err-disabled) detection in an application. As a result, when a cause is detected on an interface, the interface is placed in an err-disabled state, which is an operational state that is similar to the link-down state.
Procedure
|
Command or Action |
Purpose |
Step 1 |
config t |
Enters configuration mode. |
|
Example: |
|
|
switch# config t |
|
|
switch(config)# |
|
Step 2 |
errdisable detect cause {all | link-flap | |
Specifies a condition under which to place the |
|
loopback} |
interface in an err-disabled state. The default is |
|
|
enabled. |
|
Example: |
|
|
switch(config)# errdisable detect cause |
|
|
all |
|
|
switch(config)# |
|
Step 3 |
shutdown |
Example:
switch(config)# shutdown switch(config)#
Brings the interface down administratively. To manually recover the interface from the err-disabled state, enter this command first.
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|
Command or Action |
Step 4 |
no shutdown |
Example:
switch(config)# no shutdown switch(config)#
Purpose
Brings the interface up administratively and enables the interface to recover manually from the err-disabled state.
Step 5 |
show interface status err-disabled |
Displays information about err-disabled |
|
|
interfaces. |
|
Example: |
|
|
switch(config)# show interface status |
|
|
err-disabled |
|
Step 6 |
copy running-config startup-config |
(Optional) Copies the running configuration to |
|
|
the startup configuration. |
|
Example: |
|
|
switch(config)# copy running-config |
|
|
startup-config |
|
This example shows how to enable the err-disabled detection in all cases:
switch(config)#errdisable detect cause all switch(config)#
Enabling the Error-Disabled Recovery
You can specify the application to bring the interface out of the error-disabled (err-disabled) state and retry coming up. It retries after 300 seconds, unless you configure the recovery timer (see the errdisable recovery interval command).
Procedure
|
Command or Action |
Purpose |
Step 1 |
config t |
Enters configuration mode. |
|
Example: |
|
|
switch#config t |
|
|
switch(config)# |
|
Step 2 errdisable recovery cause {all | udld | bpduguard | link-flap | failed-port-state | pause-rate-limit}
Example:
switch(config)#errdisable recovery cause all
switch(config-if)#
Specifiesaconditionunderwhichtheinterface automatically recovers from the err-disabled state, and the device retries bringing the interface up. The device waits 300 seconds to retry. The default is disabled.
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|
Command or Action |
Purpose |
Step 3 |
show interface status err-disabled |
Displays information about err-disabled |
|
|
interfaces. |
|
Example: |
|
|
switch(config)#show interface status |
|
|
err-disabled |
|
Step 4 |
copy running-config startup-config |
(Optional)Copiestherunningconfigurationto |
|
|
the startup configuration. |
|
Example: |
|
|
switch(config)#copy running-config |
|
|
startup-config |
|
This example shows how to enable err-disabled recovery under all conditions:
switch(config)#errdisable recovery cause all switch(config)#
Configuring the Error-Disabled Recovery Interval
You can use this procedure to configure the err-disabled recovery timer value. The range is from 30 to 65535 seconds. The default is 300 seconds.
Procedure
|
Command or Action |
Purpose |
Step 1 |
config t |
Enters configuration mode. |
|
Example: |
|
|
switch#config t |
|
|
switch(config)# |
|
Step 2 |
errdisable recovery interval interval |
Example:
switch(config)#errdisable recovery interval 32
switch(config-if)#
Specifies the interval for the interface to recoverfromtheerr-disabledstate. Therange is from 30 to 65535 seconds. The default is 300 seconds.
Step 3 |
show interface status err-disabled |
Displays information about err-disabled |
|
|
interfaces. |
|
Example: |
|
|
switch(config)#show interface status |
|
|
err-disabled |
|
Step 4 |
copy running-config startup-config |
(Optional) Copies the running configuration |
|
|
to the startup configuration. |
|
Example: |
|
|
switch(config)#copy running-config |
|
|
startup-config |
|
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