Configuring the Udld Mode, Aggressive | Cisco Systems N3KC3048TP1GE

Configuring Ethernet Interfaces

Configuring the UDLD Mode

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.

To use the normal UDLD mode, you must configure one of the ports for normal mode and configure the other 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.

To configure the UDLD mode, perform this task:

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, or enables the aggressive UDLD mode.
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

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

Image 26

Cisco Systems N3KC3048TP1GE manual Configuring the Udld Mode, Command or Action Purpose Step, Switch# configure terminal

Contents

Americas Headquarters First Published February 29 Last Modified March 22Page N T E N T S Configuring VLANs Configuring Private VLANs Configuring Rapid PVST+ Configuring Multiple Spanning Tree Configuring the Port Priority Configuring Lldp Configuring Igmp Snooping Document Conventions PrefaceAudience Convention Description Italic screen font Error and System Messages Installation and Upgrade GuidesConfiguration Guides Release Notes Obtaining Documentation and Submitting a Service Request New and Changed Information for this Release Feature Description Added orSwitching mode. There are two switching Changed Release OL-26590-01 VLANs Layer 2 Ethernet Switching OverviewOverview This chapter contains the following sections STP Overview Private VLANsSpanning Tree Rapid PVST+ STP Extensions Overview STP Extensions Information About Ethernet Interfaces Configuring Ethernet InterfacesAbout the Interface Command About the Unidirectional Link Detection Parameter Feature Default Udld ConfigurationFollowing table shows the default Udld configuration Udld Aggressive and Nonaggressive Modes Following table shows the default CDP configuration About the Error-Disabled StateDefault CDP Configuration About Interface Speed About MTU Configuration Configuring Ethernet InterfacesAbout the Debounce Timer Parameters About Port Profiles Switch# configure terminal Configuring the Udld ModeCommand or Action Purpose Step Aggressive Running-config bootflash Changing an Interface Port ModeCommand or Action Running-config startup-config Transceiver inserted into it Configuring Interface SpeedSlot /port Command or Action Purpose Disabling Link Negotiation Device-id mac-address Configuring the CDP CharacteristicsAdvertise v1 Serial-number system-name Enabling or Disabling CDP Seconds Enabling the Error-Disabled Detection Example Config t Enters configuration mode Enabling the Error-Disabled RecoveryConfiguring the Error-Disabled Recovery Interval Copy running-config startup-config Errdisable recovery interval interval Configuring the Debounce TimerConfiguring the Description Parameter Show interface status err-disabled Disabling and Restarting Ethernet Interfaces Switchconfig-if# shutdown Disables the interfaceDisplaying Interface Information Command Purpose Following example shows how to display the CDP neighbors Displaying Input Packet Discard Information Default Physical Ethernet Settings Parameter Default SettingPage OL-26590-01 Understanding VLANs Configuring VLANsInformation About VLANs Vlan Ranges VLANs as Logically Defined Networks Creating, Deleting, and Modifying VLANs VLANs Numbers Range Usage Creating and Deleting a Vlan Configuring a VlanAbout the Vlan Trunking Protocol Guidelines and Limitations for VTP Vlan vlan-id vlan-range Configuring a VlanVlan-id vlan-range Active suspend Switchconfig# interface ethernetAdding Ports to a Vlan Configure terminal Enters global configuration mode Configuring a Vlan as a Routed SVISwitchconfig-if# switchport access vlan Feature interface-vlan Enables the creation of SVIs You can configure routing protocols on this interface Configuring a Vlan as a Management SVIConfiguring VTP Copy running-config Vtp passwordShow vtp password Startup-config Switch# show vlan brief id vlanid vlanrange name name Verifying Vlan ConfigurationSwitch# show running-config vlan vlanid vlanrange Summary Configuring Private VLANs Information About Private VLANs Three types of Pvlan ports are as follows Primary and Secondary VLANs in Private VLANsPrivate Vlan Ports Primary, Isolated, and Community Private VLANs Associating Primary and Secondary VLANs Private Vlan Traffic Flows Broadcast Traffic in Private VLANs Private Vlan Promiscuous TrunksPrivate Vlan Isolated Trunks Private Vlan Port Isolation Guidelines and Limitations for Private VLANs Configuring a Private VlanSwitchconfig# feature private-vlan Enabling Private VLANs Community isolated primary Configuring a Vlan as a Private VlanAssociating Secondary VLANs with a Primary Private Vlan Association Association add secondary-vlan-listRemove secondary-vlan-list Configuring an Interface as a Private Vlan Host Port Configuring an Interface as a Private Vlan Promiscuous Port Configuring the Allowed VLANs for Pvlan Trunking Ports Configuring a Promiscuous Trunk PortConfiguring an Isolated Trunk Port Switch# show feature Verifying the Private Vlan ConfigurationConfiguring Native 802.1Q VLANs on Private VLANs Switch# show interface switchport OL-26590-01 Understanding Access and Trunk Interfaces Configuring Access and Trunk InterfacesInformation About Access and Trunk Interfaces Understanding Ieee 802.1Q Encapsulation Devices in a Trunking Environment Understanding Access VLANs Header without and with 802.1Q Tag Included Understanding Native 802.1Q VLANs Understanding the Native Vlan ID for Trunk PortsUnderstanding Allowed VLANs Configuring Access and Trunk Interfaces Configuring a LAN Interface as an Ethernet Access Port Switchconfig-if# switchport host Configuring Access Host PortsConfiguring Trunk Ports On bpdu filtering and bpdu guard Specified trunk, use the switchport trunk allowed vlan Configuring the Native Vlan for 802.1Q Trunking PortsConfiguring the Allowed VLANs for Trunking Ports Port-channel number Configuring Native 802.1Q VLANs Switch# configure terminal Enters configuration mode Switch# show vlan dot1q tag native Verifying Interface ConfigurationSwitchconfig# no vlan dot1q tag Switch# show interface OL-26590-01 Cut-Through Switching Mode Configuring Switching ModesInformation About Switching Modes Store-and-Forward Switching Mode Cut-Through Switching Mode Guidelines and Limitations Guidelines and Limitations for Switching ModesLicensing Requirements for Switching Modes Store-and-Forward Switching Mode Guidelines and Limitations Enabling Store-and-Forward Switching Default Settings for Switching ModesConfiguring Switching Modes Reenabling Cut-Through Switching This example shows how to reenable cut-through switching Feature History for Switching ModesSaves the change persistently through reboots Feature Name Releases Information Understanding STP Configuring Rapid PVST+Information About Rapid PVST+ STP Overview Understanding How a Topology is Created Understanding the Bridge ID Bit Bit extended system ID field is part of the bridge IDBridge Priority Value 8192 4096 2048 1024 512 256 128 Understanding BPDUs Election of the Root Bridge Creating the Spanning Tree Topology Understanding Rapid PVST+ Rapid PVST+ Overview Rapid PVST+ BPDUs Rapid PVST+ Flag Byte in Bpdu Proposal and Agreement Handshake Proposal and Agreement Handshaking for Rapid Convergence Variable Description Protocol TimersPort Roles Port States Rapid PVST+ Port State Overview Blocking State Operational Status Port State Enabled Blocking Learning Yes Forwarding DisabledSynchronization of Port Roles Topology? Processing Superior Bpdu Information Spanning-Tree Dispute Mechanism Port Cost Port Priority Rapid PVST+ and Ieee 802.1Q TrunksRapid PVST+ Interoperation with Legacy 802.1D STP Bandwidth Enabling Rapid PVST+ Configuring Rapid PVST+Rapid PVST+ Interoperation with 802.1s MST Enabling Rapid PVST+ per Vlan Mode rapid-pvstSwitch# configure Terminal Configuring the Root Bridge ID Configuring a Secondary Root Bridge Spanning-tree mst max-ageconfiguration commands Configuring the Rapid PVST+ Port Priority Vlan vlan-list port-priority priority Pathcost method long short Configuring the Rapid PVST+ Pathcost Method and Port CostConfiguring the Rapid PVST+ Bridge Priority of a Vlan Vlan vlan-id cost value auto Vlan-range hello-time hello-time Configuring the Rapid PVST+ Hello Time for a VlanSwitchconfig# spanning-tree vlan Specifying the Link Type Configuring the Rapid PVST+ Forward Delay Time for a VlanConfiguring the Rapid PVST+ Maximum Age Time for a Vlan Vlan-range forward-time forward-time Switch# show running-config spanning-tree all Verifying Rapid PVST+ ConfigurationsSwitch# clear spanning-tree detected-protocol Restarting the Protocol This example shows how to display spanning tree status Switch# show spanning-tree optionsSpanning tree configuration OL-26590-01 MST Overview Configuring Multiple Spanning TreeInformation About MST MST Regions MST BPDUs IST, CIST, and CST Overview MST Configuration InformationIST, CIST, and CST Spanning Tree Operation Within an MST Region Spanning Tree Operations Between MST Regions MST Terminology MST Regions, Cist Regional Roots, and CST Root Hop Count Boundary Ports Spanning-Tree Dispute Mechanism MST Boundary Ports Port Cost and Port Priority Interoperability with Ieee 802.1D You must enable MST Rapid PVST+ is the default Configuring MSTMST Configuration Guidelines Enabling MST Switchconfig# no spanning-tree mode mst Entering MST Configuration ModeSwitchconfig# spanning-tree mode mst Mst configuration Spanning-tree mst Switchconfig# spanning-tree mstSpecifying the MST Name Instance-id vlan vlan-range Specifying the MST Configuration Revision NumberSpecifying the Configuration on an MST Region Name Version Mapping and Unmapping VLANs to MST Instances Default MSTI, which is the CistThis example shows how to map Vlan 200 to Msti Same Msti and their associated primary Vlan Configuring the Root BridgeSynchronize For all private VLANs 104 Mst instance-id root Configuring the Port PrioritySwitchconfig# no spanning-tree Optional Configuring the Port Cost Configuring the Switch Priority Hello-time seconds Configuring the Hello TimeConfigures the hello time for all MST instances. The hello Switch is alive. For seconds, the range is from 1 to 10, Configuring the Forwarding-Delay TimeConfiguring the Maximum-Aging Time Mst max-age seconds Configuring the Maximum-Hop CountConfiguring Pvst Simulation Globally Max-hops hop-count Configuring Pvst Simulation Per Port Switchconfig-if#spanning-tree mst simulate pvst disable Command Verifying MST ConfigurationsRestarts MST on entire switch or Specified interfaces Information About STP Extensions Configuring STP ExtensionsAbout STP Extensions Understanding STP Port Types Understanding Bridge Assurance Understanding Bpdu Guard Understanding Bpdu Filtering Is disabledDefault Enable Disable Enabled/Disabled Port returns to Understanding Loop Guard Understanding Root Guard Configuring Spanning Tree Port Types Globally Configuring STP ExtensionsSTP Extensions Configuration Guidelines Port type edge default Port type network default Port type edge Switchconfig# interface typeSwitchconfig-if# spanning-tree Edge ports. Edge ports immediately transition to Port type network Ports. If you enable Bridge Assurance, it automaticallyEnabling Bpdu Guard Globally Enabling Bpdu Guard on Specified Interfaces Edge bpdufilter default Switchconfig-if# no spanning-tree bpduguardEnables Bpdu Filtering by default on all Filtering is disabled by default Bpdufilter Bpdufilter enable disableEnabling Bpdu Filtering on Specified Interfaces Guard is disabled Loopguard defaultNormal and network ports. By default, global Loop Enabling Loop Guard Globally Verifying STP Extension Configuration Guard loop root none 126 Configuring Lldp Configuring Global Lldp Commands Optionalswitch# show lldp Displays Lldp configurations Ensure that the Lldp feature is enabled on the switchHoldtime reinit timer Configuring Interface Lldp Commands Transmit This example shows how to display Lldp timer information This example shows how to display Lldp counters Configuring a Static MAC Address Configuring the MAC Address TableConfiguring MAC Addresses Information About MAC Addresses Switch# configure terminal Enters global configuration mode Configuring the Aging Time for the MAC TableSwitchconfig-# no mac-address-table static Macaddress vlan vlan-id Switch# show mac-address-table aging-time Verifying the MAC Address ConfigurationSwitchconfig# clear mac-address-table dynamic Defined in the switch This example shows how to display the MAC address table This example shows how to display the current aging time Configuring Igmp Snooping Information About Igmp Snooping Igmp Snooping Switch IGMPv1 and IGMPv2 Igmp Forwarding IGMPv3Igmp Snooping Querier Configuring Igmp Snooping Parameters Parameter Description Snooping No ip igmp snooping mrouter vpc-peer-linkNo ip igmp snooping mrouter Last-member-query-interval Snooping explicit-trackingSnooping fast-leave Snooping querier IP-address Verifying Igmp Snooping Configuration 141 142 Configuring Traffic Storm Control Information About Traffic Storm Control Traffic Storm Guidelines and Limitations Broadcast Suppression Configures traffic storm control for traffic Configuring Traffic Storm ControlSwitchconfig-if# storm-control broadcast On the interface. The default state is Verifying Traffic Storm Control Configuration Traffic Storm Control Example ConfigurationDefault Traffic Storm Settings Parameters Default D E Mstp Cist root 93 CIST, described 91 CST 91 Rstp 68, 71, 75, 89 active topology 71 Bpdu Adding ports to Private Configuring VLANs