Table Of Contents
Cisco NX-OS Interfaces Commands
clear counters interface port-channel
port-channel load-balance ethernet
show interface port-channel counters
show port-channel compatibility-parameters
show port-channel load-balance
show port-channel rbh-distribution
show running-config interface port-channel
Cisco NX-OS Interfaces Commands
This chapter describes the Cisco NX-OS interfaces commands.
bandwidth (interface)
To set the inherited and received bandwidth values for an interface, use the bandwidth command in interface configuration mode. To restore the default values, use the no form of this command.
bandwidth {kbps | inherit [kbps]}
no bandwidth {kbps | inherit [kbps]}
Syntax Description
Defaults
1000000 kbps
Command Modes
Interface configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
The bandwidth command sets an informational parameter to communicate only the current bandwidth to the higher-level protocols; you cannot adjust the actual bandwidth of an interface using this command.
Note
This is a routing parameter only. It does not affect the physical interface.
The bandwidth inherit command controls how a subinterface inherits the bandwidth of its main interface.
The no bandwidth inherit command enables all subinterfaces to inherit the default bandwidth of the main interface, regardless of the configured bandwidth. If a bandwidth is not configured on a subinterface, and you use the bandwidth inherit command, all subinterfaces will inherit the current bandwidth of the main interface. If you configure a new bandwidth on the main interface, all subinterfaces will use this new value.
If you do not configure a bandwidth on the subinterface and you configure the bandwidth inherit command on the main interface, the subinterfaces will inherit the specified bandwidth.
In all cases, if an interface has an explicit bandwidth setting configured, then that interface will use that setting, regardless of whether the bandwidth inheritance setting is in effect.
This command does not require a license.
Examples
This example shows how to configure all subinterfaces off this main interface to inherit the configured bandwidth:
switch(config-if)# bandwidth inherit 30000Related Commands
carrier-delay
To set the carrier delay on an interface, use the carrier-delay command. To return to the default carrier delay value, use the no form of this command.
carrier-delay {sec | {msec value}}
no carrier-delay
Syntax Description
sec
Seconds of delay. The range of values is from 0 to 60.
value
Milliseconds of delay. The range of values is from 0 to 1000.
Defaults
The default is 2 seconds or 50 milliseconds.
Command Modes
Interface
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Note
If a link goes down and comes back up before the carrier delay timer expires, the down state is effectively filtered, and the rest of the software on the device is not aware that a link-down event occured. A large carrier delay timer results in fewer link-up/link-down events being detected. When you set the carrier delay time to 0, the device detects each link-up/link-down event that occurs.
Note
In most environments, a lower carrier delay time is better than a higher one. The exact value that you choose depends on the nature of the link outages and how long you expect these linkages to last in your network. If your data links are subject to short outages (especially if those outages last less time than it takes for your IP routing to converge) you should set a long carrier delay value to prevent these short outages from causing unnecessary churn in your routing tables. However, if you outages tend to be longer, then you may want to set a shorter carrier delay time so that the outages are detected sooner, and the IP route convergence begins and ends sooner.
This command does not require a license.
Examples
This example shows how to set the carrier delay timer to 20 minutes for VLAN 6:
switch(config)# interface vlan 6switch(config-if)# carrier-delay 20switch(config-if)#Related Commands
channel-group
To assign and configure a physical interface to a port-channel group, use the channel-group command. To remove the channel-group configuration from the interface, use the no form of this command.
channel-group number [force] [mode {active | on | passive}]
no channel-group [number]
Syntax Description
number
Number of channel group. Maximum number of port channels that can be configured is 192 across all VDCs, and the range of values is from 1 to 4096.
force
Forces the interface to join the channel group, although some parameters are not compatible. See Usage Guidelines below for information on the compatibility parameters and which ones can be forced.
mode
Specifies the port-channel mode of the interface.
on
This is the default channel mode, and all port channels that are not running LACP remain in this mode. If you attempt to change the channel mode to active or passive before enabling LACP, the device returns an error message.
After you enable LACP globally, by using the feature lacp command, you enable LACP on each channel by configuring the channel mode as either active or passive. An interface in this mode does not initiate or respond to LACP packets. When an LACP attempts to negotiate with an interface in the on state, it does not receive any LACP packets and becomes an individual link with that interface; it does not join the channel group.The default mode is on.
active
Specifies that when you enable the Link Aggregation Control Protocol (LACP), this command enables LACP on the specified interface. Interface is in active negotiating state, in which the port initiates negotiations with other ports by sending LACP packets.
passive
Specifies that when you enable LACP, this command enables LACP only if an LACP device is detected.The interface is in a passive negotiation state, in which the port responds to LACP packets that it receives but does not initiate LACP negotiation.
Defaults
None
Command Modes
Interface configuration
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Use this command to create a channel group that includes the interface that you are working on and to add or remove specific interfaces from the channel group. Use this command to move a port from one channel group to another. You enter the channel group that you want the port to move to; the device automatically removes the specified from its present channel group and adds that port to the specified channel group.
After you enable LACP globally, by using the feature lacp command, you enable LACP on each channel by configuring the channel mode as either active or passive. A port channel in the on channel mode is a pure port channel and can aggregate a maximum of eight ports. It does not run LACP.
You cannot change the mode for an existing port channel or any of its interfaces if that port channel is not running LACP; the channel mode remains as on. The system returns an error message if you try.
All ports in one port channel must be in the same virtual device context (VDC). With LACP enabled, this requirement applies to the possible eight active ports and the possible eight standby ports. The port channels can originate in one VDC (with all ports in that channel in the same VDC) and partner with a port channel in another VDC (again, all ports in that channel must be in that VDC).
Use the no form of this command to remove the physical interface from the port channel. When you delete the last physical interface from a port channel, the port channel remains. To delete the port channel completely, use the no form of this interface port-channel command.
The compatibility check includes the following operational attributes:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Use the show port-channel compatibility-parameters command to see the full list of compatibility checks that the Cisco NX-OS uses.
You can only add interfaces configured with the channel mode set to on to static port channels, that is without a configured aggregation protocol. And you can only add interfaces configured with the channel mode as active or passive to port channels that are running LACP.
You can configure these attributes on an individual member port. If you configure a member port with an incompatible attribute, Cisco NX-OS suspends that port in the port channel.
Alternatively, you can force ports with incompatible parameters to join the port channel as long the following parameters are the same:
•
•
•
•
•
•
When the interface joins a port channel, some of its individual parameters are removed and replaced with the values on the port channel, as follows:
•
•
•
•
•
•
•
•
•
•
•
Also, many interface parameters remain unaffected with the interface joins or leaves a port channel, as follows:
•
•
•
•
•
•
•
•
•
•
If subinterfaces are configured for the port-channel interface and a member port is removed from the port channel, the configuration of the port-channel subinterface is not propagated to the member ports.
Any configuration changes that you make in any of the compatibility parameters to the port-channel interface are propagated to all interfaces within the same channel group as the port channel (for example, configuration changes are also propagated to the physical interfaces that are not part of the port channel but are part of the channel group).
You do not have to create a port-channel interface before you assign a physical interface to a channel group. A port-channel interface is created automatically when the channel group gets its first physical interface, if it is not already created.
You can create either a Layer 2 or a Layer 3 port channel by entering the interface port-channel command or when the channel group gets its first physical interface assignment. The port channels are not created at run time or dynamically.
This command does not require a license.
Examples
This example shows how to add an interface to LACP channel group 5 in active mode:
switch(config-if)# channel-group 5 mode activeswitch(config-if)#Related Commands
clear counters interface port-channel
To clear the statistics for all interfaces for the specified port channel, use the clear counters interface port-channel command.
clear counters interface port-channel channel-number
Syntax Description
Defaults
None
Command Modes
Any command mode
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
This command does not require a license.
Examples
This example shows how to clear all the counters for the specified port-channel:
switch(config)# clear counters interface port-channel 5switch(config) #Related Commands
show interface port-channel counters
Displays information about port-channel statistics.
clear lacp counters
To clear the statistics for all interfaces for Link Aggregation Control Protocol (LACP) groups, use the clear lacp counters command.
clear lacp counters [interface port-channel channel-number]
Syntax Description
Defaults
None
Command Modes
Any command mode
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
If you enter this command for a static port-channel group, without the aggregation protocol enabled, the device ignores the command.
If you do not specify a channel number, the LACP counters for all LACP port groups are cleared.
This command does not require a license.
Examples
This example shows how to clear all the LACP counters:
switch(config)# clear lacp countersswitch(config) #This example shows how to clear all LACP counters for the LACP port-channel group 20:
switch(config)# clear lacp counters interface port-channel 20switch(config)#Related Commands
encapsulation dot1Q
To enable IEEE 802.1Q encapsulation of traffic on a specified subinterface in a virtual LAN (VLAN), use the encapsulation dot1q command in subinterface configuration mode. To disable encapsulation, use the no form of this command.
encapsulation dot1Q vlan-id
no encapsulation dot1Q vlan-id
Syntax Description
vlan-id
VLAN to set when the interface is in access mode; valid values are from 1 to 4094, except for the VLANs reserved for internal switch use.
Defaults
No encapsulation
Command Modes
Subinterface configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
IEEE 802.1Q encapsulation is configurable on Ethernet interfaces. IEEE 802.1Q is a standard protocol for interconnecting multiple switches and routers and for defining VLAN topologies.
Use the encapsulation dot1q command in subinterface range configuration mode to apply a VLAN ID to the subinterface.
This command does not require a license.
Examples
This example shows how to enable dot1Q encapsulation on a subinterface for VLAN 30:
switch(config-subif)# encapsulation dot1q 30Related Commands
feature interface-vlan
To enable the creation of VLAN interfaces (switched virtual interfaces [SVI]), use the feature interface-vlan command in global configuration mode. To disable the VLAN interface feature, use the no form of this command.
feature interface-vlan
no feature interface-vlan
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Global configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
You must use the feature interface-vlan command before you can create VLAN interfaces.
This command does not require a license.
Examples
This example shows how to enable the interface VLAN feature:
switch(config)# feature interface-vlanRelated Commands
feature lacp
To enable Link Aggregation Control Protocol (LACP) port channeling on the device, use the feature lacp command. To disable LACP on the device, use the no form of this command.
feature lacp
no feature lacp
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Global configuration
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
You must remove all the LACP configuration parameters from all port channels on the device before you can disable LACP. You cannot disable LACP while LACP configurations remain on the device.
Even after you enable LACP globally, you do not have to run LACP on all port channels on the device. You enable LACP on each channel mode using the channel-group mode command.
This command does not require a license.
Examples
This example shows how to enable LACP port channeling on the device:
switch(config)# feature lacpswitch(config)#Related Commands
feature tunnel
To enable the creation of tunnel interfaces, use the feature tunnel command in global configuration mode. To disable the tunnel interface feature, use the no form of this command.
feature tunnel
no feature tunnel
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Global configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
You must use the feature tunnel command before you can create tunnel interfaces.
This command requires the Enterprise license.
Examples
This example shows how to enable the interface tunnel feature:
switch(config)# feature tunnelRelated Commands
interface loopback
To create a loopback interface and enter interface configuration mode, use the interface loopback command. To remove a loopback interface, use the no form of this command.
interface loopback number
no interface loopback number
Syntax Description
Defaults
None
Command Modes
Global configuration
Interface configurationSupported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Use the interface loopback command to create or modify loopback interfaces.
This command does not require a license.
Examples
This example shows how to create a loopback interface:
switch(config)# interface loopback 50switch(config-if)#Related Commands
show interface loopback
Displays information about the traffic on the specified loopback interface.
interface port-channel
To create a port-channel interface and enter interface configuration mode, use the interface port-channel command. To remove a logical port-channel interface or subinterface, use the no form of this command.
interface port-channel channel-number
no interface port-channel channel-number
Syntax Description
channel-number
Channel number that is assigned to this port-channel logical interface. The range of valid values is from 1 to 4096.
Defaults
None
Command Modes
Global configuration
Interface configurationSupported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Use the interface port-channel command to create or delete port-channel groups and to enter the interface configuration mode for the port channel.
You can create port channels implicitly using the bandwidth (interface) command or explicitly using the feature tunnel command.
A port can belong to only one channel group.
You can create subinterfaces on a Layer 3 port-channel interface. However, you cannot add a Layer 3 interface that has existing subinterfaces to a port channel.
Note
The Link Aggregation Control Protocol (LACP) system ID is unique for each VDC, and channel-group numbers and names can be re-used in different VDCs.
When you use the interface port-channel command, follow these guidelines:
•
•
•
This command does not require a license.
Examples
This example shows how to create a port-channel group interface with channel-group number 50:
switch(config)# interface port-channel 50switch(config-if)#Related Commands
interface tunnel
To create a tunnel interface and enter interface configuration mode, use the interface tunnel command. To remove a tunnel interface, use the no form of this command.
interface tunnel number
no interface tunnel number
Syntax Description
Defaults
None
Command Modes
Global configuration
Interface configurationSupported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Use the interface tunnel command to create or modify tunnel interfaces.
Cisco NX-OS supports the GRE header defined in IETF RFC 2784. Cisco NX-OS does not support tunnel keys and other options from IETF RFC 1701.
You can configure IP tunnels only in the default virtual device context (VDC).
This command requires the Enterprise license.
Examples
This example shows how to create a tunnel interface:
switch(config)# interface tunnel 50switch(config-if)#Related Commands
interface vlan
To create a VLAN interface and enter interface configuration mode, use the interface vlan command. To remove a VLAN interface, use the no form of this command.
interface vlan vlan-id
no interface vlan vlan-id
Syntax Description
vlan-id
VLAN to set when the interface is in access mode; valid values are from 1 to 4094, except for the VLANs reserved for the internal switch use.
Defaults
None
Command Modes
Global configuration
Interface configurationSupported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Use the interface vlan command to create or modify VLAN interfaces.
The VLAN interface is created the first time that you enter the interface vlan command for a particular VLAN. The vlan-id argument corresponds to the VLAN tag that is associated with the data frames on an Inter-Switch Link (ISL), the IEEE 802.1Q-encapsulated trunk, or the VLAN ID that is configured for an access port.
This command does not require a license.
Examples
This example shows how to create a VLAN interface for VLAN 50:
switch(config)# interface vlan 50switch(config-if)#Related Commands
feature interface-vlan
Enables the ability to create VLAN interfaces.
show interface vlan
Displays information about the traffic on the specified VLAN interface.
lacp port-priority
To set the priority for the physical interfaces for the Link Aggregation Control Protocol (LACP), use the lacp port-priority command. To return the port priority to the default value, use the no form of this command.
lacp port-priority priority
no lacp port-priority
Syntax Description
Defaults
32768
Command Modes
Interface configuration
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Each port configured to use LACP has an LACP port priority. You can accept the default value of 32768 for the LACP port priority, or you can configure a value between 1 and 65535. LACP uses the port priority in combination with the port number to form the port identifier. The port priority is used with the port number to form the port identifier. The port priority is used to decide which ports should be put into standby mode when there is a hardware limitation that prevents all compatible ports from aggregating or when you have more than eight ports configured for the channel group.
When setting the priority, note that a higher number means a lower priority.
This command does not require a license.
Examples
This example shows how to set the LACP port priority for the interface to 2000:
switch(config-if)# lacp port-priority 2000switch(config-if)#Related Commands
lacp system-priority
To set the system priority of the device for the Link Aggregation Control Protocol (LACP), use the lacp system-priority command. To return the system priority to the default value, use the no form of this command.
lacp system-priority priority
no lacp system-priority
Syntax Description
Defaults
32768
Command Modes
Global configuration
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
Each device that runs LACP has an LACP system priority value. You can accept the default value of 32768 for this parameter, or you can configure a value between 1 and 65535. LACP uses the system priority with the MAC address to form the system ID and also during negotiation with other systems. The system ID is unique for each virtual device context (VDC).
When setting the priority, note that a higher number means a lower priority.
This command does not require a license.
Examples
This example shows how to set the LACP system priority for the device to 2500:
switch(config-if)# lacp system-priority 2500switch(config-if)#Related Commands
show lacp
Displays LACP information.
show lacp system identifier
Displays information on the LACP system identifier.
medium
To set the medium mode for an interface, use the medium command in interface configuration command. To remove the entry, use the no form of this command.
medium {broadcast | p2p}
no medium {broadcast | p2p}
Syntax Description
broadcast
Configures the interface as a broadcast medium.
p2p
Configures the interface as a point-to-point medium.
Defaults
None
Command Modes
Interface configuration
Supported User Rolesnetwork-admin
vdc-adminCommand History
Usage Guidelines
The medium command is used to configure the interface as broadcast or point to point.
This command does not require a license.
Examples
This example shows how to configure the interface for point-to-point medium:
switch(config-if)# medium p2pport-channel load-balance ethernet
To set the load-balancing method among the interfaces in the channel-group bundle, use the port-channel load-balance ethernet command. To return the system priority to the default value, use the no form of this command.
port-channel load-balance ethernet method [module slot]
no port-channel load-balance ethernet [method [module slot]]
Syntax Description
method
Load-balancing method. See the "Usage Guidelines" section for a list of valid values.
module slot
(Optional) Specifies the module slot number.
Defaults
Layer 2 packets—src-dst-mac
Layer 3 packets—src-dst-ip
Command Modes
Global configuration
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
When you do not specify a module, you are configuring load balancing for the entire device. When you use the module parameter, you are configuring load balancing for the specified modules
Valid method values are as follows:
•
•
•
•
•
•
•
•
•
Note
Use the module argument to configure the module independently for port-channeling and load-balancing mode. When you do this, the remaining module use the current load-balancing method configured for the entire device, or the default method if you have not configured a method for the entire device. When you enter the no argument in conjunction with a module argument, the load-balancing method for the specified module takes the current load-balancing method that is in use for the entire device. If you configured a load-balancing method for the entire device, the specified module uses that configured method, rather than the default src-dst-ip/src-dst-mac. The per module configuration takes precedence over the load-balancing method configured for the entire device.
You can configure one load-balancing mode for the entire device, a different mode for specified modules, and yet another mode for other specified modules. The per module configuration takes precedence over the load balancing configuration for the entire device.
Use the option that provides the balance criteria with the greatest variety in your configuration. For example, if the traffic on a port channel is going only to a single MAC address and you use the destination MAC address as the basis of port channel load balancing, the port channel always chooses the same link in that port channel; using source addresses or IP addresses might result in better load balancing.
This command does not require a license.
Examples
This example shows how to set the load-balancing method for the entire device to use the source port:
switch(config)# port-channel load-balance ethernet src-portswitch(config)#Related Commands
show port-channel load-balance
Displays information on port-channel load balancing.
show interface counters trunk
To display the counters for Layer 2 switch port trunk interfaces, use the show interface counters trunk command.
show interface {ethernet slot/port} counters trunk
Syntax Description
ethernet slot/port
Specifies the module number and port number for the trunk interface that you want to display.
Defaults
None
Command Modes
Any command mode
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
The device supports only IEEE 802.1Q encapsulation. This command also displays the counters for trunk port channels.
This command does not require a license.
Examples
This example shows how to display the counters for a trunk interface. This display shows the frames transmitted and received through the trunk interface, as well as the number of frames with the wrong trunk encapsulation:
switch# show interface ethernet 2/9 counters trunk---------------------------------------------------------------------Port TrunkFramesTx TrunkFramesRx WrongEncap---------------------------------------------------------------------Ethernet2/9 0 0 0switch#Related Commands
show interface port-channel
To display descriptive information about port channels, use the show interface port-channel command.
show interface port-channel channel-number [brief | description | flowcontrol | status | switchport | trunk]
Syntax Description
Defaults
None
Command Modes
Any command mode
Supported User Rolesnetwork-admin
vdc-admin
Command History
Usage Guidelines
To display more statistics for the specified port channels, use the show interface port-channel counters command.
This command does not require a license.
Examples
This example shows how to display information for a specific port channel. This command displays statistical information gathered on the port channel at 1-minute intervals:
switch(config)# show interface port-channel 50port-channel50 is down (No operational members)Hardware is Port-Channel, address is 0000.0000.0000 (bia 0000.0000.0000)MTU 1500 bytes, BW 100000 Kbit, DLY 10 usec,reliability 255/255, txload 1/255, rxload 1/255Encapsulation ARPA</
