Cisco Nexus 1000V Interface Configuration Guide, Release 4.0(4)SV1(2)
Configuring Interface Parameters
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Configuring Interface Parameters

Table Of Contents

Configuring Interface Parameters

Information About the Basic Interface Parameters

Description Parameter

Speed and Duplex Modes

Port MTU Size

Administrative Status

Cisco Discovery Protocol

Port Channel Parameter

Guidelines and Limitations

Configuring the Basic Interface Parameters

Specifying an Interface to Configure

Configuring a Description

Dedicating Bandwidth to One Port

Configuring the Interface Speed and Duplex Modes

Configuring the System Jumbo MTU Size

Configuring the MTU Size

Configuring the Interface MTU Size

Configuring Bandwidth

Configuring the Throughput Delay

Shutting Down and Activating an Interface

Enabling or Disabling CDP

Clearing the Interface Counters

Verifying the Basic Interface Parameters

Feature History for Basic Interface Parameters


Configuring Interface Parameters


This chapter describes how to configure the basic interface parameters or the parameters that are shared by multiple interfaces.

This chapter includes the following sections:

Information About the Basic Interface Parameters

Guidelines and Limitations

Configuring the Basic Interface Parameters

Verifying the Basic Interface Parameters

Feature History for Basic Interface Parameters


Note To configure Layer 2 access or trunking interfaces, see Chapter 2 "Configuring Interface Parameters."


Information About the Basic Interface Parameters

This section includes the following topics:

Description Parameter

Speed and Duplex Modes

Port MTU Size

Administrative Status

Cisco Discovery Protocol

Port Channel Parameter

Description Parameter

For the vEthernet, Ethernet, and management interfaces, you can configure the description parameter to provide a recognizable name for the interface. Using a unique name for each interface allows you to quickly identify the interface when you are looking at a listing of multiple interfaces.

For information about setting the description parameter for port channel interfaces, see the "Configuring a Port Channel Description" section.

For information about configuring this parameter for other interfaces, see the "Configuring a Description" section.

Speed and Duplex Modes

The speed and duplex modes are interrelated for each Ethernet and management interface. By default, each of these interfaces autonegotiates its speed and duplex modes with the other interface, but you can change these settings. If you change the settings, be sure to use the same speed and duplex mode settings on both interfaces, or use autonegotiation for at least one of the interfaces. Table 2-1 shows the settings that work for each type of Ethernet and management interface.

Table 2-1 Speed and Duplex Mode Settings Used for Ethernet and Management Interfaces

Module Type
Speed Mode Setting
Duplex Mode Setting
Operational Speed (Mbps)
Operational Duplex Mode

32-port 10 GE Ethernet

Auto1

Auto1

10,000

Full

48-port 10/100/1000 Ethernet

Auto1

Auto1

1000

Full

     

10 or 100

Half

 

1000

Auto1 or full

1000

Full

 

100

Auto1 or half

100

Half

   

Full

100

Full

 

10

Auto1 or half

10

Half

   

Full

10

Full

Management

Auto1

Auto1

1000

Full

     

10 or 100

Half

 

1000

Auto1 or full

1000

Full

 

100

Auto1 or half

100

Half

   

Full

100

Full

 

10

Auto1 or half

10

Half

   

Full

10

Full

1 Default setting


For information about setting the speed and duplex modes for port channel interfaces, see the "Configuring the Speed and Duplex Settings for a Port Channel Interface" section.

For information about setting the speed and duplex modes for other interfaces, see the "Configuring the Interface Speed and Duplex Modes" section.

Port MTU Size

The maximum transmission unit (MTU) size specifies the maximum frame size that an Ethernet port can process. For transmissions to occur between two ports, you must configure the same MTU size for both ports. A port drops any frames that exceed its MTU size.

By default, The MTU size for each port is 1500 bytes, which is the IEEE 802.3 standard for Ethernet frames. Larger MTU sizes are possible for more efficient processing of data with less overhead. The larger frames, called jumbo frames, can be up to 9000 bytes in size, which is also the default system jumbo MTU size.

For a Layer 2 port, you can configure an MTU size as the system default of 1500 bytes or the system default jumbo MTU size of 9000 bytes.


Note If you change the system jumbo MTU size, Layer 2 ports automatically use the system default MTU size of 1500 bytes unless you specify differently for some or all of those ports.


For information about setting the MTU size, see the "Configuring the MTU Size" section.

Administrative Status

The administrative-status parameter determines whether an interface is up or down. When an interface is administratively down, it is disabled and unable to transmit data. When an interface is administratively up, it is enabled and able to transmit data.

For more information, see the following sections:

Shutting Down and Restarting a Port Channel Interface.

Shutting Down and Activating an Interface.

Cisco Discovery Protocol

The Cisco Discovery Protocol (CDP) is a Layer 2 protocol that enables two devices that run CDP to learn about each other. You can use CDP to troubleshoot the network by displaying information about the neighboring devices that are linked through each interface. By default, CDP is enabled.

To configure CDP, see the "Enabling or Disabling CDP" section.

Port Channel Parameter

A port channel is an aggregation of physical interfaces that comprise a logical interface. You can bundle up to eight individual interfaces into a port channel to provide increased bandwidth and redundancy. Port channeling also load balances traffic across these physical interfaces. The port channel stays operational if at least one physical interface within the port channel is operational.

Any configuration changes that you apply to the port channel are applied to each interface member of that port channel.

To configure port channels, see the "Configuring Port Channels" section.

Guidelines and Limitations

Interface parameters have the following guidelines and limitations:

Fiber-optic Ethernet ports must use Cisco-supported transceivers. To verify that the ports are using Cisco-supported transceivers, use the show interface transceivers command. Interfaces with Cisco-supported transceivers are listed as functional interfaces.

Flow control, that is using IEEE 802.3x pause frames for controlling flow, is not supported.

You usually configure Ethernet port speed and duplex mode parameters to auto to allow negotiation of the speed and duplex modes between ports. If you decide to configure the port speed and duplex modes manually for these ports, consider the following:

If you set the Ethernet port speed to auto, the device automatically sets the duplex mode to auto.

If you enter the no speed command, the device automatically sets both the speed and duplex parameters to auto (the no speed command produces the same results as the speed auto command).

If you configure an Ethernet port speed to a value other than auto (for example, 10, 100, or 1000 Mbps), you must configure the connecting port to match. Do not configure the connecting port to negotiate the speed.


Note The device cannot automatically negotiate the Ethernet port speed and duplex modes if the connecting port is configured to a value other than auto.



Note Changing the Ethernet port speed and duplex mode configuration might shut down and reenable the interface.


Configuring the Basic Interface Parameters

This section includes the following topics:

Specifying an Interface to Configure

Configuring a Description

Dedicating Bandwidth to One Port

Configuring the Interface Speed and Duplex Modes

Configuring the MTU Size

Configuring Bandwidth

Configuring the Throughput Delay

Shutting Down and Activating an Interface

Enabling or Disabling CDP

Specifying an Interface to Configure

Use this procedure to specify an interface to configure.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

SUMMARY STEPS

1. config t

2. interface interface

3. show interface interface

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

interface interface

Example:

n1000v(config)# interface ethernet 2/1

n1000v(config-if)#

Specifies the interface that you are configuring.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

For a vEthernet port, use vethernet number, where number is a number from 1 to 1048575.

Note You do not need to add a space between the interface type and the slot/port or interface number. For example, for the Ethernet slot 4, port 5 interface, you can specify either "ethernet 4/5" or "ethernet4/5."

Step 3 

show interface interface

Example:

n1000v(config-if)# show interface ethernet 2/1

Displays the current configuration of interfaces.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

For a vEthernet port, use vethernet number, where number is a number from 1 to 1048575.

Configuring a Description

Use this procedure to add a description to a vEthernet or management interface.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

A description is case-sensitive and can be up tp 80 alphanumeric characters in length.

SUMMARY STEPS

1. config t

2. interface interface

3. description string

4. show interface interface

5. exit

6. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

interface interface

Example:

n1000v(config)# interface ethernet 2/1

n1000v(config-if)#

Specifies the interface that you are configuring.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

For a vEthernet port, use vethernet number, where number is a number from 1 to 1048575.

Step 3 

description string

Example:

n1000v(config-if)# description Ethernet port 3 on module 1.

n1000v(config-if)#

Adds the description for the interface and saves it in the running configuration.

For string, the description can be up to 80 alphanumeric characters.

Note You do not need to use quotations around descriptions that include spaces.

Step 4 

show interface interface

Example:

n1000v(config)# show interface ethernet 2/1

Displays the interface status, which includes the description.

Step 5 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits the interface mode.

Step 6 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to set the interface description to Ethernet port 24 on module 3:

n1000v# config t 
n1000v(config)# interface ethernet 3/24
n1000v(config-if)# description server1
n1000v(config-if)#

Dedicating Bandwidth to One Port

Use this procedure to dedicate bandwidth to one port by doing the following:

1. Administratively shutting down the four interfaces in the group.

2. Changing the rate mode to dedicated.

3. Administratively bringing the dedicated port up.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

SUMMARY STEPS

1. config t

2. interface ethernet slot/port, ethernet slot/port, ethernet slot/port, ethernet slot/port

3. shutdown

4. interface ethernet slot/port

5. rate-mode dedicated

6. no shutdown

7. show interface ethernet slot/port

8. exit

9. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

interface ethernet slot/port, ethernet slot/port, ethernet slot/port, ethernet slot/port

Example:

n1000v(config)# interface ethernet 3/1, ethernet 3/3, ethernet 3/5, ethernet 3/7

n1000v(config-if)#

Specifies the Ethernet interfaces to configure, and enters interface configuration mode.

The example shows how to specify one port for the dedicated mode.

Step 3 

shutdown

Example:

n1000v(config)# shutdown

Administratively shuts down the ports in the running configuration.

Step 4 

interface ethernet slot/port

Example:

n1000v(config)# interface ethernet 3/1

n1000v(config)#

Specifies the first Ethernet interface in a group of interfaces.

Step 5 

rate-mode dedicated

Example:

n1000v(config-if)# rate-mode dedicated

n1000v(config-if)#

Full bandwidth of 10 Gb is dedicated to one port in the running configuration. When you dedicate the bandwidth, all subsequent commands for the port are for dedicated mode.

Step 6 

no shutdown

Example:

n1000v(config-if)# no shutdown

Brings the port administratively up in the running configuration.

Step 7 

show interface ethernet slot/port

Example:

n1000v(config-if)# show interface ethernet 3/1

Displays the interface information including the current rate mode.

Step 8 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits interface configuration mode.

Step 9 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to configure the dedicated mode for Ethernet port 4/17 in the group that includes ports 4/17, 4/19, 4/21, and 4/23:

n1000v# config t 
n1000v(config)# interface ethernet 4/17, ethernet 4/19, ethernet 4/21, ethernet 4/23
n1000v(config-if)# shutdown
n1000v(config-if)# interface ethernet 4/17
n1000v(config-if)# rate-mode dedicated
n1000v(config-if)# no shutdown
n1000v(config-if)#

Configuring the Interface Speed and Duplex Modes

Use this procedure to configure the interface speed and duplex modes.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

The interface speed and duplex modes are interrelated, so you should configure both at the same time. To see the speeds and duplex modes that you can configure together for Ethernet and management interfaces, see the "Speed and Duplex Modes" section.


Note The interface speed that you specify can affect the duplex mode used for an interface, so you should set the speed before setting the duplex mode. If you set the speed for autonegotiation, the duplex mode is automatically set to be autonegotiated. If you specify a speed of 10 Mbps or 100 Mbps, the port is automatically configured to use half-duplex mode, but you can specify full-duplex mode instead. If you specify a speed of 1000 Mbps (1 Gbps) or faster, full duplex is automatically used.


Make sure that the remote port has a speed setting that supports your changes for the local port. If you want to set the local port to use a specific speed, you must set the remote port for the same speed or set the local port to autonegotiate the speed.

SUMMARY STEPS

1. config t

2. interface interface

3. speed {{10 | 100 | 1000 | {auto [10 100 [1000]]}} | {10000 | auto}}

4. duplex {full | half | auto}

5. show interface interface

6. exit

7. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Enters the global configuration mode.

Step 2 

interface interface

Example:

n1000v(config)# interface ethernet 2/1

n1000v(config-if)#

Specifies the interface that you are configuring.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

For a vEthernet port, use vethernet number, where number is a number from 1 to 1048575.

Step 3 

speed {{10 | 100 | 1000 | {auto [10 100 [1000]]}} | {10000 | auto}}

Example:

n1000v(config-if)# speed 1000

n1000v(config-if)#

For Ethernet ports on the 48-port 10/100/1000 modules, sets the speed at 10 Mbps, 100 Mbps, or 1000 Mbps, or sets the port to auto negotiate its speed with the other 10/100/1000 port on the same link.

For Ethernet ports on the 32-port 10-Gigabit Ethernet modules, sets the speed at 10,000 Mbps (10 Gbps) or sets the port to autonegotiate its speed with the other 10-Gigabit Ethernet port on the link.

For management interfaces, sets the speed as 1000 Mbps or sets the port to autonegotiate its speed.

Step 4 

duplex {full | half | auto}

Example:

n1000v(config-if)# duplex full

Specifies the duplex mode as full, half, or autonegotiate.

Step 5 

show interface interface

Example:

n1000v(config)# show interface mgmt0

Displays the interface status, which includes the speed and duplex mode parameters.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

For a vEthernet port, use vethernet number, where number is a number from 1 to 1048575.

Step 6 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits interface configuration mode.

Step 7 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to set the speed of Ethernet port 1 on the 48-port 10/100/1000 module in slot 3 to 1000 Mbps and full-duplex mode:

n1000v# config t 
n1000v(config)# interface ethernet 3/1
n1000v(config-if)# speed 1000
n1000v(config-if)# duplex full
n1000v(config-if)#

Configuring the System Jumbo MTU Size

Use this procedure to configure the system jumbo MTU size, which can be used to specify the MTU size for Layer 2 interfaces.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

You can specify an even number of bytes between 1500 and 9000. If you do not configure the system jumbo MTU size, it defaults to 1500 bytes.

SUMMARY STEPS

1. config t

2. system jumbomtu size

3. show running-config

4. interface ethernet slot/port

5. mtu size

6. exit

7. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

system jumbomtu size

Example:

n1000v(config)# system jumbomtu 8000

Specifies the system jumbo MTU size. Use an even number between 1500 and 9000.

Step 3 

show running-config

Example:

n1000v(config)# show running-config

Displays the current operating configuration, including the system jumbo MTU size.

Step 4 

interface ethernet slot/port

Example:

n1000v(config)# interface ethernet 2/2

n1000v(config-if)#

Specifies an interface to configure and enters interface configuration mode.

Step 5 

mtu size

Example:

n1000v(config-if)# mtu 8000

Specifies either the default MTU size of 1500 or the system jumbo MTU size that you specified earlier.

Step 6 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits the interface mode.

Step 7 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to configure the system jumbo MTU as 8000 bytes and how to change the MTU specification for an interface that was configured with the previous jumbo MTU size:

n1000v# config t 
n1000v(config)# system jumbomtu 8000
n1000v(config)# show running-config
n1000v(config)# interface ethernet 2/2
n1000v(config-if)# switchport
n1000v(config-if)# mtu 8000
n1000v(config-if)# 

Configuring the MTU Size

Use this section to configure the size of the maximum transmission unit (MTU) for Layer 2 Ethernet interfaces.

This section includes the following topics:

Configuring the Interface MTU Size

Configuring the System Jumbo MTU Size

Configuring the Interface MTU Size

Use this procedure to configure the MTU for all interfaces.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

You can specify either of the following for MTU size:

The system default MTU size of 1500 bytes.

A system jumbo MTU size between 1500 and 9000 bytes.

To configure the jumbo MTU size, see the "Configuring the System Jumbo MTU Size" section.

SUMMARY STEPS

1. config t

2. interface ethernet slot/port

3. mtu size

4. show interface ethernet slot/port

5. exit

6. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

interface ethernet slot/port

Example:

n1000v(config)# interface ethernet 3/1

n1000v(config-if)#

Specifies an Ethernet interface to configure, and enters interface configuration mode.

Step 3 

mtu size

Example:

n1000v(config-if)# mtu 9216

Specifies either the default MTU size (1500) or the system jumbo MTU size (9000) unless you have changed the system jumbo MTU size.

Step 4 

show interface ethernet slot/port

Example:

n1000v(config-if)# show interface type slot/port

Displays the interface status, which includes the MTU size.

Step 5 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits interface configuration mode.

Step 6 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to configure the Ethernet interface 3/1 with the default MTU size of 1500 bytes:

n1000v# config t 
n1000v(config)# interface ethernet 3/1
n1000v(config-if)# mtu 1500
n1000v(config-if)#

Configuring Bandwidth

Use this procedure to configure bandwidth for Ethernet interfaces.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

The physical level uses an unchangeable bandwidth of 1 GB, but you can configure a value from 1 to 10,000,000 Kb for Level 3 protocols.

SUMMARY STEPS

1. config t

2. interface ethernet slot/port

3. bandwidth value

4. show interface ethernet slot/port

5. exit

6. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

interface ethernet slot/port

Example:

n1000v(config)# interface ethernet 3/1

n1000v(config-if)#

Specifies an Ethernet interface to configure, and enters interface configuration mode.

Step 3 

bandwidth value

Example:

n1000v(config-if)# bandwidth 1000000

Assigns the specified bandwidth to the interface in the running configuration. The bandwidth is an information-only value from 1 to 10,000,000.

Step 4 

show interface ethernet slot/port

Example:

n1000v(config-if)# show interface ethernet slot/port

Displays the interface status, which includes the bandwidth value.

Step 5 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits interface configuration mode.

Step 6 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to configure an informational value of 1,000,000 Kb for the Ethernet slot 3, port 1 interface bandwidth parameter:

n1000v# config t 
n1000v(config)# interface ethernet 3/1
n1000v(config-if)# bandwidth 1000000
n1000v(config-if)#

Configuring the Throughput Delay

Use this procedure to configure throughput delay for the Ethernet interface informational display.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

SUMMARY STEPS

1. config t

2. interface ethernet slot/port

3. delay value

4. show interface ethernet slot/port

5. exit

6. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

interface ethernet slot/port

Example:

n1000v(config)# interface ethernet 3/1

n1000v(config-if)#

Specifies an interface to configure, and enters interface configuration mode.

Step 3 

delay value

Example:

n1000v(config-if)# delay 10000

Assigns the delay time to the interface in the running configuration. The delay time is specified in tens of microseconds.

Step 4 

show interface ethernet slot/port

Example:

n1000v(config)# show interface ethernet 3/1

Displays the interface status, which includes the throughput-delay time.

Step 5 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits the interface configuration mode.

Step 6 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to configure the throughput-delay time to 100,000 microseconds for the Ethernet port 3/1:

n1000v# config t 
n1000v(config)# interface ethernet 3/1
n1000v(config-if)# delay 10000
n1000v(config-if)#

Shutting Down and Activating an Interface

Use this procedure to shut down and restart Ethernet or management interfaces.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

When you shut down an interface, it becomes disabled. As a result, the following occurs:

The output of monitoring commands show it as being down.

Dynamic routing protocols relay this information to other network servers.

The interface is not included in routing updates.

When the interfaces are shut down.

To activate an interface that has been shut down, you must restart the device.

SUMMARY STEPS

1. config t

2. interface interface

3. shutdown

4. show interface interface

5. no shutdown

6. show interface interface

7. exit

8. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

interface interface

Example 1:

n1000v(config)# interface ethernet 2/1

n1000v(config-if)#

Specifies the interface that you are configuring.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

Step 3 

shutdown

Example:

n1000v(config-if)# shutdown

Disables the interface in the running configuration.

Step 4 

show interface interface

Example:

n1000v(config-if)# show interface ethernet 2/1

Displays the interface status, which includes the administrative status.

Step 5 

no shutdown

Example:

n1000v(config-if)# no shutdown

Reenables the interface in the running configuration.

Step 6 

show interface interface

Example:

n1000v(config-if)# show interface ethernet 2/1

Displays the interface status, which includes the administrative status.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

Step 7 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits the interface configuration mode.

Step 8 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to change the administrative status for Ethernet port 3/1 from disabled to enabled:

n1000v# config t 
n1000v(config)# interface ethernet 3/1
n1000v(config-if)# shutdown
n1000v(config-if)# no shutdown
n1000v(config-if)#

Enabling or Disabling CDP

Use this procedure to enable or disable the Cisco Discovery Protocol (CDP) for Ethernet and management interfaces.

BEFORE YOU BEGIN

Before beginning this procedure, you must know or do the following:

You are logged in to the CLI in EXEC mode.

Make sure that CDP is enabled at both ends of the link.

SUMMARY STEPS

1. config t

2. interface interface

3. cdp enable
no cdp enable

4. show cdp interface interface

5. exit

6. copy running-config startup-config

DETAILED STEPS

 
Command
Purpose

Step 1 

config t

Example:

n1000v# config t

n1000v(config)#

Places you into the global configuration mode.

Step 2 

interface interface

Example 1:

n1000v(config)# interface ethernet 3/1

n1000v(config-if)#

Specifies the interface that you are configuring.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

Step 3 

cdp enable

Example:

n1000v(config-if)# cdp enable

Enables CDP for the interface in the running configuration.

To work, this parameter must be enabled for both interfaces on the same link.

 

no cdp enable

Example:

n1000v(config-if)# no cdp enable

Disables CDP for the interface in the running configuration.

As soon as you disable CDP for one of two interfaces, CDP is disabled for the link.

Step 4 

show cdp interface interface

Example:

n1000v(config-if)# show cdp interface interface

Displays the CDP status for the interface in the running configuration.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

Step 5 

exit

Example:

n1000v(config-if)# exit

n1000v(config)#

Exits the interface configuration mode.

Step 6 

copy running-config startup-config

Example:

n1000v(config)# copy running-config startup-config

(Optional) Saves the running configuration persistently through reboots and restarts by copying it to the startup configuration.

EXAMPLES

The following example shows how to enable CDP for Ethernet port 3/1:

n1000v# config t 
n1000v(config)# interface ethernet 3/1
n1000v(config-if)# cdp enable
n1000v(config-if)#
 
   

The following example shows how to disable CDP for Ethernet port 3/1:

n1000v# config t 
n1000v(config)# interface ethernet 3/1
n1000v(config-if)# no cdp enable
n1000v(config-if)#

Clearing the Interface Counters

Use this procedure to clear the Ethernet and management interface counters. You can perform this task from the EXEC mode, configuration mode, or interface configuration mode.

SUMMARY STEPS

1. clear counters interface

2. show interface interface

DETAILED STEPS

 
Command
Purpose

Step 1 

clear counters interface

Example:

n1000v# clear counters ethernet 2/1

n1000v#

Clears the Ethernet or management counters for the specified interface:

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

Step 2 

show interface interface

Displays the interface status, which includes the counters.

The interface argument is defined as follows:

For an Ethernet port, use ethernet slot/port, where slot is the module slot number and port is the port number.

For the management interface, use mgmt 0 or mgmt0.

EXAMPLES

The following example shows how to clear and reset the counters on Ethernet port 5/5:

n1000v# clear counters ethernet 5/5 
n1000v#

Verifying the Basic Interface Parameters

Use the commands listed here to verify the basic interface parameters

To display port configuration information, use one of the following commands:

Command
Purpose

show cdp

Displays the CDP status.

show interface interface

Displays the configured states of one or all interfaces.

show interface brief

Displays a table of interface states.

show interface switchport

Displays the status of Layer 2 ports.


Feature History for Basic Interface Parameters

This section provides the feature history for basic interface parameters.

Feature Name
Releases
Feature Information

Basic interface parameters

4.0

This feature was introduced.